The 25 Best Sci-Fi TV Series of the 21st Century, Ranked

[Editor’s Note: this list was originally published in April 2017. It has since been updated to coincide with the Season 2 premiere of “Severance.”]

It hardly needs mentioning, but not all science fiction is created equal. Even as a term, it’s difficult to pinpoint exactly what constitutes sci-fi, especially in a medium like TV that can change so much from week to week or season to season. So when we took stock of the best TV shows from the past two decades, we tried to take a hard line separating the sci-fi from the fantasy.

That’s not to say that a few of the shows might have an odd sword or two, but most of what we tried to single out here imagines a world markedly different from our own. Some take place in reimagined futures, while others take a sharper focus on the present with some key, otherworldly changes.

So, follow us down the rabbit hole to some of the most thrilling, thought-provoking —and in many cases, utterly horrifying — alternate realities that TV has brought us in recent years.

With editorial contributions from Ben Travers, Steve Greene, Liz Shannon Miller, and Hanh Nguyen.

25. “The 4400”

“The 4400”Inc/Kobal/REX/Shutterstock

First off: Anyone who watched “The 4400” during its initial run on USA was likely not surprised to see Mahershala Ali — or Mahershalalhashbaz Ali, as he was known then — eventually become an Oscar-winning actor. As Richard Tyler, one of the 4,400 individuals plucked from history to be deposited in the year 2004 with mysterious abilities, Ali was one of the show’s most engaging performers, an empathetic presence who sold us on the show’s emotional drama while we waited to find out exactly how and why this seemingly random collection of strangers had been transported to the future. Not every plot twist of this series worked, but the mysteries kept us hooked during its run, as the show managed to never lose sight of its human stories even while taking on large-scale sci-fi drama.

24. “Silo”

‘Silo,’ Rebecca Ferguson©Apple TV/Courtesy Everett Collection

A feat of worldbuilding, “Silo” features one of the most imaginative and fleshed-out fictional futures in recent TV memory. Based on the novel trilogy by author Hugh Howey, Graham Yost’s Apple TV+ series is set thousands of years in the future, where all of humanity is seemingly confined to a giant underground silo to protect themselves from the toxic and dangerous outside world. Our window into this landscape is engineer Juliette (Rebecca Ferguson), who’s investigation into the death of her lover leads her to question the lost history behind the silo. Ferguson’s fierce performance complements the show, a grim but always compelling thriller about fighting against the powers that be. —WC

23. “Sense8”

“Sense8”Murray Close/Netflix

The science part of the science fiction on “Sense8” is merely the entry point to a fantastic story of human nature. Eight individuals born around the world on the same day realize they have a psychic connection that lets them feel and experience things simultaneously but also take over each other’s bodies in order to help them through trying situations. This wholly unique device demonstrated how we are not alone as long as there is acceptance of the universal human experience.

Batshit nuts at times, the show has created indelible scenes in which the Cluster or Sensates experience events around the globe as if they’re in the same room, whether it’s sex (ah, the famous orgy scenes), swimming, executing a jailbreak or even childbirth. The Wachowskis’ artistic eyes have created some of the most breathtaking images seen on TV, and their genius shines when it comes to crowd scenes where it seems like everyone is filled with the same, contagious elation. There’s no party like a “Sense8” party, and it’s no wonder that the emotional force of this series inspired its devoted fanbase to petition for the show to continue after Season 2’s cliffhanger ending. It’s a testament to the voice of that global cluster that Netflix finally saw sense (ha!) and announced a series-capping movie that would round out the story.

22. “The Middleman”

Given how hard it is to explain exactly what was going on with the ABC Family sci-fi series, we understand why it might have been canceled. But the cheerful homage to decades of pop culture was a delight to watch, especially thanks to charming lead performances by Natalie Morales and Matt Keeslar. “The Middleman” was dense with references, but it also kept its central characters fun and relatable as they dealt with no shortage of absurd scenarios, drawn from the widest reaches of sci-fi and fantasy tropes.

21. “The 100”

Sometimes, you watch a post-apocalyptic drama and you think, “Hmmmm, feels like they pulled their punches to some degree.” This is not true of “The 100.” One of the most brutal shows we’ve ever seen, “The 100” also happens to be rich with big sci-fi ideas, even as it pits its characters against each other in semi-regular battles to the death. The CW series’ commitment to coming up with shocks and surprises has proven fascinating to behold, even as it finds new depths to its mythology.

20. Terminator: The Sarah Connor Chronicles

“Terminator: The Sarah Connor Chronicles”WB TV/Kob/REX/Shutterstock

Arguably, the “Terminator” franchise is only really a franchise because of “The Sarah Connor Chronicles.” Sure, the first two films reaped in profits and awards hand over fist, but nothing since then has stuck. “Terminator 3: Rise of the Machines,” “Salvation,” and “Genisys” all flopped stateside, with each film making significantly less money than the last, and none earned enough raves to pass the test of time.

But “The Sarah Connor Chronicles,” which lasted 31 episodes over two seasons, is the third piece of the puzzle; the missing ingredient needed to make fans of the franchise believe there doesn’t have to be an end. Where the later films have failed to sustain a sense of wonder and excitement, the Lena Headey-starring series picks up right after “T2” and never looks back. Solid action, an aptly winding plot, and a strong lead turn make this one worth remembering — and successful enough that many fans still do. It makes sense: After all, “Terminator” always was Sarah’s story.

19. “Dollhouse”

“Dollhouse”Fox TV/Kobal/REX/Shutterstock

Even though Joss Whedon’s “Firefly” lasted only one season compared to “Dollhouse’s” two, this series’ premise brought about a different kind of controversy. Super-skilled people known as Actives or Dolls are “programmed” to be whatever a wealthy client wants them to be for a job: an assassin, a thief, a sex slave, an expert. Once they’re done with the gig, the Dolls’ memories are wiped and they sleep in an underground bunker, treated as mere objects and given codenames like Echo (Eliza Dushku), Victor (Enver Gjokaj) and Sierra (Dichen Lachman).

There’s no denying that the series starts out with a sense of ickiness as these people become mere inanimate tools. But once the series hits its stride, it’s an incredibly moving and sympathetic look at the deep-seated, transformative effects of trauma. Combined with the claustrophobic yet complete world that Whedon dreams up, the ballsy, profound show is one that was before its time and may have fared better on cable or today’s streaming services.

18. “Better Off Ted”

“Better Off Ted”

Technically, “Better Off Ted” is much more a comedy than full-on sci-fi. But the show belongs on this list because of the imagination that fueled the inventions being created by Veridian Dynamics, the fake corporation at the heart of the show. From weaponizing pumpkins to cryogenically freezing its employees, Veridian gave the short-lived ABC sitcom an out-there edge, one that added just enough darkness to make the show far more than just another workplace comedy.

17. “3%”

3%Netflix

If you haven’t seen this Brazilian dystopian series yet, get thee to a Netflix immediately. Set in the not-so-distant future, “3%” imagines a world in which overpopulation and the depletion of natural resources creates a society where only a few can enjoy life’s simple necessities. Every year, the people living in poverty who turn 20 are offered the chance to take a series of tests called The Process, in which only 3 percent will pass and get to live among the privileged and elite on the Offshore.

These extreme circumstances reveal what lengths people will go to for survival, and The Process exposes the darkest and most heroic parts of human nature. Picking a favorite candidate is often an exercise in futility when these characters reveal more of their true nature. Mysterious, suspenseful and at times horrifying, “3%” is an addictive look at humanity and one that reflects back on ourselves.

16. “Westworld”

Jeffrey Wright and Anthony Hopkins.John P. Johnson/HBO

Dolores. Maeve. Bernard. Dr. Robert Ford. The Man in Black. These names already evoke a sense of excitement; vivid memories of distinct visuals, like a fly crawling over an unblinking eye or stunning twists, like, well, virtually all of Season 1. HBO’s new drama about a theme park populated by robot hosts is just that: new. But Jonathan Nolan and Lisa Joy showed us plenty we’d never seen before in a gorgeous, invigorating, and thought-provoking journey to the darkest and lightest sides of humanity. The key to making it all tick wasn’t buried in the basement of a church: It was in each character, who — whether they’re man or machine — we already care about deeply. And that’s exactly the point.

15. “Star Trek: Strange New Worlds”

“Star Trek: Strange New Worlds”CBS

Even the most devoted of “Star Trek” fans can admit that Gene Roddenberry’s sci-fi world hasn’t produced essential entertainment in years (decades, even). Or at least, that’s how it was before “Strange New Worlds” debuted on Paramount+ and became the best entry in the beloved sci-fi franchise since “Deep Space Nine” wrapped up in 1999. A delightful throwback to the days where shows could tell strong standalone stories instead of bloated series-long arcs, the prequel to the groundbreaking original series has one of the franchise’s most colorful and likable casts (with highlights including Anson Mount’s dashing captain Christopher Pike, Rebecca Romijn’s badass Una-Chin Riley, and Christina Chong’s guarded La’an Noonien-Singh), and an expansive tone that can fluctuate between traumatic war stories to flighty musical episodes to small-scale character pieces without missing a beat. The only thing wrong with “Strange New Worlds” is the fact that we only get 10 episodes of it a season. —WC

14. “Colony”

“Colony”Isabella Vosmikova/USA Network

Dark from the beginning, the alien occupation drama created by Ryan Condal and Carlton Cuse got even darker during Season 2. (If suicide bombings make you uncomfortable, it might be best to avoid this one.) But the way in which “Colony” uses the metaphor at the center of its premise to explore what living under occupied rule might do to a family, to a society, has kept this show engaging over both seasons. We’re anxious and excited to see what might come next.

13. “Misfits”

Iwan Rheon, “Misfits”Hulu

A working-class British alternative to the squeaky clean Peter Parker story, this Channel 4 sci-fi series lets its superheroes also be teenagers. Dealing with the hormonal problems of young adulthood, it also punctured the idea that people with extraordinary powers are also blessed with the ability to handle them. With a dry wit and a merciless approach to its roving cast of characters, “Misfits” found just as much satisfaction in watching these teenagers discover themselves as it did the usual trappings of a superhero origin story. With a world-class theme song and a hazy filter that did just as much to muddy our perspective as the occasional peek into a character’s brain, this was a story about special abilities that wasn’t afraid to stay unpolished.

12. “For All Mankind”

A show that takes big swings and oftentimes misses, “For All Mankind” nonetheless hits hard when it connects. Dad television of the highest order, the Apple TV+ alternate history show looks at a world where the space race never stopped, taking a hard sci-fi approach to a timeline where the United States pools infinite resources into besting Russia on the path to concurring the galaxy. Over four seasons, “For All Mankind” sometimes proves too expansive for its own good, but when the show delivers — such as in the exquisite and unforgettable Season 2 finale — it’s unmissable television. —WC

11. “Orphan Black”

Tatiana Maslany and Tatiana Maslany in “Orphan Black.”Ken Woroner/BBC AMERICA

Cloning isn’t all that scary if our future looks like Tatiana Maslany. The Emmy-winning actress playing multiple characters is the No. 1 reason this show is as good as it is. Each of the characters she plays have such distinct identities that it’s easy to forget that all of them come from one performer.

With the vibrancy of each of the characters, the show is at its best when the overarching conspiracies take a backseat to simple character interactions. Alison with Felix, Helena with Donnie, Helena with Alison, Sarah with Alison, all the clones together — no matter what the combination of is, the dialogue sparkles and the bigger corporate plot becomes mere background. But this is precisely why the show is so strong. It works in the most basic way, placing human characters in unusual, technology-fueled circumstances. The women of “Orphan Black” own their bodies and biology, no matter what some scientist has done with their DNA: It’s one of the most feminist statements on TV.

10. “Legion”

“Legion”Chris Large/FX

Perhaps we should’ve expected Noah Hawley would be a good fit for sci-fi when he brought UFOs into “Fargo.” That successful blend of cold reality with inexplicable phenomena functioned as an effective preview of “Legion.” The wild, confounding, and exhilarating comic book adaptation carried a central premise that kept viewers on edge all the way through its opening season: Is David Haller (Dan Stevens) crazy, or does he have otherworldly powers? By keeping that mystery at the core of the show, Hawley grounded his science fiction in a reality we could all identify with. Who hasn’t imagined being the most powerful man in the world?

9. “Fringe”

“Fringe”Fox-TV/Kobal/REX/Shutterstock

A spiritual sequel to “The X-Files,” featuring Joshua Jackson, John Noble and Lieutenant Daniels from “The Wire”? Hell yes. “Fringe” was most notable for the fearless chances it took from season to season. Experimenting with form and function, it slowly shed its procedural roots to become one of broadcast television’s most imaginative sci-fi series, leaping through realities and timelines with relative abandon. “Fringe” was also rich with humor, anchored by an amazing lead performance by star Anna Torv, and often far smarter than we gave it credit for. Plus, it was fun. The troubled final season, largely taking place in the not-too-distant future and pushing the show into full-on dystopia, wasn’t the show at its best. But Seasons 2-4 were dramatic, romantic and ridiculous, in the best ways possible.

8. “The Expanse”

Dominique Tipper in “The Expanse.”Shane Mahood/Syfy

You want hard sci-fi? Then you want “The Expanse.” One of the most science-obsessed shows on this list, the drama based on James S.A. Corey’s novels is rich with big ideas about how interplanetary exploration might not just change society, but our conception of humanity in general. After two seasons, the relationships between Earthers, Martians, Belters and beyond have become more complicated than viewers might have ever expected. But the show’s devotion to creating a fully realized, fully believable future universe has made it one of modern TV’s more striking sci-fi adventures.

7. “Severance”

‘Severance’Courtesy of Jon Pack / Apple TV+

Few science-fiction shows create a world that feels as familiar yet as alien as “Severance.” The Apple TV+ hit is a feat of production design courtesy of Jeremy Hindle, who created an endless maze of sterile white hallways and bizarre green workstations that looks like a workplace out of your darkest nightmares. Populating this mysterious corporate hellscape are a variety of talented actors who seamlessly portray essentially two different characters, as workers for the Lumen corporation who have their consciousness split between a workplace and home self. It could be a fairly facile and pat allegory about modern late-stage capitalism and the eroding idea of “work-life balance” in industries that barely view their workers as humans. Instead, the cleverly crafted series combines strong performances (especially from lead Adam Scott as the head of the severed workforce that plots a revolution and Tramell Tillman as a menacing corporate suit), “Lost”-indebted worldbuilding and scripting from showrunner Dan Erickson, and coolly comfortable direction from Ben Stiller to create sci-fi that feels urgent and all-too-relatable to the current moment. —WC

6. “Futurama”

The red-headed cult favorite step-brother to the juggernaut that is “The Simpsons,” “Futurama” has survived multiple rounds of cancelations and reboots, with various degrees of fluctuating quality to match. But fans remain devoted to Matt Groening and David X. Cohen’s series because of that magic original four-season run, which perfectly paired sitcom cartoon storytelling with sci-fi parody and storylines to create something utterly unique. Set in the far-flung world of the year 3000, “Futurama” always smartly crafted an imagined future that was both familiar (capitalism, prejudice, and other 21st century concerns still stuck around) and fantastical (a robot devil, a moon amusement park), and populated it with characters that were both hilarious and lovable. And in its fish out of water audience surrogate Fry, the show managed to find an avenue for poignant stories reckoning with the passage of time and loss, while always matching it with a pitch-perfect “Star Trek” parody or zany scientific experiment to take the edge off. —WC

5. “Firefly”

“Firefly”Snap Stills/REX/Shutterstock

Blending elements of science fiction and its most antithetical genre long before “Westworld” came along (though not before the 1973 Michael Crichton film), “Firefly” also forged a multicultural future from familiar American standards and East Asian cultures. The inclusive vision of tomorrow, where English and Mandarin Chinese are two commonly accepted languages is slightly undercut by the fact that there weren’t really any Asian actors in the show, but we suspect (hope?) this troubling oversight would’ve been fixed if Joss Whedon’s cult classic series had lasted more than 14 episodes.

Overall, “Firefly” has aged well because most of its themes were ahead of their time. From the existential theorizing to Nathan Fillion’s leading man status to the two main genres driving it all, Whedon’s space opera soared without relying on massive space battles. The Civil War had already been fought and lost. These are the survivors, and we get to know them very well, hoping against hope their drive to succeed continues to heal their souls. We’d follow these browncoats anywhere, especially with Captain Reynolds leading the charge.

4. “Lost”

“Lost”Touchstone/ABC/REX/Shutterstock

One of the most dissected pieces of entertainment of the Internet age, it’s almost impossible to talk about “Lost” as a single unit. Over its six seasons, the show went through countless iterations of what it was attempting to answer and what its characters sought from this strange island world. As a concise bit of ensemble storytelling, perhaps the show was more successful as a generations-spanning multi-timeline story than it was when things ventured into the realm of the metaphysical. But throughout all of its time on the air, the show was a fascinating Rorschach test for an emerging kind of audience. “Lost” was a fundamental text for an era of direct fan interaction, doing just as much to shape the expectations of genre fandom as it did to shape the stories of Jack, Kate, Sawyer and the rest. Anchored by a impressive family tree of writers and directors that helped bring the story to life, not to mention the dynamite Hall of Fame TV score by Michael Giacchino, it was the kind of show that found success on a number of creative levels. The ambition, scope and breathless, week-to-week obsession may never be equaled on network television.

3. “Doctor Who”

“Doctor Who“

While technically “Doctor Who” has existed for more than 50 years, well out of the range of the 21st century criterion, most Whovians can admit that the modern series that began with Christopher Eccleston in 2005 is a different beast from the “Who” of the past. The genius of “Doctor Who” is that it takes all of the best sci-fi tropes – time-travel, aliens, technology and the vast, unknowable aspects of space – and compresses it into one person. The Doctor is arguably one of the most intriguing and complex characters to be ever created, and not just because he (or now she!) has been played by multiple actors over the years. Adventurous, frightening, heartwarming, hilarious — all of these aspects of the Doctor are also words that could describe the show. At its core, “Doctor Who” is a rollicking adventure tale for us mere humans who identify with the Doctor’s earthling companions. It’s about exploring the furthest reaches of the imagination, no TARDIS necessary.

2. “Battlestar Galactica”

“Battlestar Galactica” proved that even with the galaxy as a canvas, stories in space can still be as compelling as a group of people trapped on a ship. That restrictive framework put the focus on character, forming a solid base for a story that could react to real-world developments unfolding as the audience was watching. A vehicle for social commentary as well as a mystifying series about the nature of identity, loyalty and optimism, it proved there was plenty of life in a premise that some thought was decades past its relevancy. It’s also a shining example of what stories can do when they consider the value of institutions, law and the standards we hold to each other under extraordinary circumstances. It’s certainly not the first piece of sci-fi to use robots as a way to understand the finer points of humanity, but on the TV side, it might just be the best.

1. “Black Mirror”

“Black Mirror“Endemol UK

Few pieces of entertainment can pull off the tricky balance between being a time capsule of the moment and also existing in a timeless world all its own. But that’s exactly what Charlie Brooker’s twisted view of a not-too-distant future has done in each installment, regardless of its network home. Traversing the gap between worlds of the real and worlds of the mind, “Black Mirror” is a show that draws bleakness from human obsession and, in its most recent episodes, has even found a room for a glimmer of hope. For a tech-centric view of the future, it also has plenty to say about how we remember what’s most important to us. There are memories you can relive, ones that you can live inside, and the ones that you literally can’t escape from. As a series built on a number of alternate realities, it finds the scariest truths of how we live our lives in the present.

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