What are the best sci-fi series of all time? Boldly going where no man has gone before, science fiction is one of the cornerstones of genre TV. Exploring brave new worlds, giving actors fascinating roles to dig into, and presenting a moral dilemma or three, good sci-fi shows give plenty of food for thought.
But, if you’re trying to chart a course for the best TV series, what space-age adventure is worth the investment? Time-traveling series are cool, but maybe you prefer things metaphysical. And there are how many Star Trek captains, again? Nobody likes having their time wasted, especially not an entire season’s worth to figure out something isn’t for you.
We’ve watched old favorites, including the best Marvel series and Star Wars series, and a few new arrivals, to create a definitive list of the best sci-fi series for you to explore. Spaceships, clones, cool gadgets, conspiracies, robots of every description, and even some digital monsters, it’s all here. You can go to space, stay on Earth, find human drama, or try to leave us all behind. Either way, hit the telecom – it’s time for beaming up.
20. Twilight Zone (1959-1964)
The Twilight Zone is one of the best TV series of all time and is a great way for every sci-fi fan to experience all the corners that this genre has to offer. With its anthology-style format, some episodes deal with time travel, others show us space exploration, then we also have chapters dealing with alternative dimensions, dystopian societies, and sci-fi horror too.
In short, this 1950s show never gets old and is also the reason why tons of our favorite science fiction shows and movies exist today. Rob Serling, the series’ creator, introduced the genre to the mainstream public and cemented a lot of sci-fi tropes and themes that still exist today.
19. Westworld (2016-2022)
During a time when AI is becoming more prevalent, Westworld is one of the best and most tense shows you can watch right now. Created by Jonathan Nolan and Lisa Joy and based on the 1973 Western of the same name, the show unpacks the age-old robot question – breaking down machines’ relationships with people and the dangers they can pose.
The story is simple – an amusement park for the rich is filled with android hosts. Corporations, data harvesting, and the consequences of greed ensue and eventually filter into the real world. With a breakdown of the ethics of AI and a captivating script full of twists and turns, it is no wonder how this show has become the favorite of many and the winner of nine Emmy Awards.
18. Severance (2022-present)
In 2022, the world was introduced to one of the most captivating and mysterious sci-fi series in years, Severance. Here is a show that hits a bit closer to home, showing us a not-so-far-away dystopian future where worker rights are in jeopardy and corporations are more like a cult than traditional businesses.
Mark is a Lumon Industries employee who agrees to enter a ‘severance’ program. All of his work memories are separated from the rest of his life – meaning there are essentially two versions of himself that have no idea about each other’s actions, past, or daily activities. However, as the series goes on, we realize that there is something sinister about the severance push, and Mark finds himself in the center of a dark and dangerous conspiracy.
Severance is one of the best Apple TV shows you can watch and explores the collective sci-fi horror that is corporations stripping us of our humanity and rights – effectively turning us into androids. It is brilliant, and we can’t wait for the Severance season 2 release date.
17. The Last of Us (2023-present)
An adaptation of one of the finest PlayStation games of all time, The Last of Us expertly moved its story from controller to TV remote, with Joel, Ellie, and the rest of the characters the same in spirit as their source material counterparts. Following a cross-country journey across a zombie-ridden America, it’s as scary as it is deft.
It can be slightly trauma-porn-ish at times, even more so than the dark world of the games, but its attention to detail and themes is mined from the same quality narrative, meaning it’s just as affecting, complex, and brutal as we remembered. Further seasons are sure to be discourse magnets, and we can’t wait to continue wrestling with the world’s consequences when Part II is folded into this batter.
16. Stranger Things (2016-present)
Stranger Things is synonymous with Netflix at its peak, and it’s easy to see why. With high-quality production value, endearing characters we watched grow up, and stakes that culminated in an outstanding fourth season, it’s one of the best Netflix series.
Whether it’s the battle against villains, the tension of the characters in danger, or its finest musical moments (here’s to you, Max), Stranger Things would be in danger of becoming too saturated if it weren’t for its ability to rearrange itself each season. This is true ‘event television’, and the season 4 two-part finale had us in its clutches from start to finish.
15. Cowboy Bebop (1997–1998)
Starting off with one of the best anime series ever, Cowboy Bebop is one of the major crossover hits of ’90s anime. In the year 2071, bounty hunters Spike Spiegel, Jet Black, Faye Valentine, Ed, and their pet corgi Ein are constantly in search of work aboard their ship, the Bebop. They face rivals and personal demons alike in their hopes of gaining lucrative contracts in the intergalactic Wild West.
Kinetic and thrilling, the seamless blend of futuristic technology with the gunslinging of your average Western has been hugely influential. Director Shinichirō Watanabe originally wanted to make an anime movie, and said that when producing the episodes, he kept that format in mind. The 26 episodes enjoy the grandeur of one with the length of the other, giving the best of both worlds.
14. Star Trek: Voyager (1995–2001)
Including a Star Trek series was a given, and no matter which one, it’d be controversial. We’ve gone with Voyager, the ship led by Captain Kathryn Janeway. When her crew is warped into the delta quadrant, they spend years exploring the region while trying to find a way home.
The concept of being lost at sea yet still representing the Federation makes it a middle ground between the human drama of Deep Space Nine and the moralizing of The Next Generation. Sometimes you can really see the barrel being scraped for ideas, but this Star Trek entry is rarely predictable and feels quite singular in the grand canon.
13. Terminator: The Sarah Connor Chronicles (2007–2009)
We’ve had several Terminator 3s; this is by far the best one. Subverting what we get when watching the Terminator movies in order, Sarah and John Connor are warped forward in time, from 1999 to 2007, to prevent another Judgment Day from happening.
A T-900 is on their side, but a T-888 and the FBI aren’t far behind. The show embraces how little the franchise makes sense and stays committed regardless, with a younger Lena Headey of Game of Thrones and Dredd fame in the lead role. And guess what? She’s a perfect Sarah Connor.
12. The Outer Limits (1963–1965)
“There is nothing wrong with your television set. Do not attempt to adjust the picture.” If you haven’t seen any of the Outer Limits, you’ve likely seen it satirized or riffed on. ABC’s darker, stranger cousin of The Twilight Zone was often decidedly more morbid than Rod Serling’s anthology, painting a nihilistic future for mankind.
Sometimes that means irreversible infection due to space travel, or clones being used as hired killers. One of the more famous episodes is ‘The Zanti Misfit’, where aliens make us use Earth as their prison. Grim, yet riveting.
11. Digimon (1999–Present)
Cool kids watched Pokémon, really cool kids watched Digimon. Originally a wave of branded Tamagotchis, the lovable virtual pets became their own franchise, an anime about camaraderie, growing pains, and loss and heartache at the center of it.
A group of kids at summer camp are chosen as the DigiDestined, and transported to the Digital World where they meet their digital monsters – in the late ’90s, this all sounded much cooler. Together, the anime characters work to defeat the Dark Masters. Each season has another generation of chosen ones, while previous groups pop in as they get older. Disarmingly affecting its prolonged, ever-changing arcs.
10. Dark (2017–2020)
A show that requires you to have its Wikipedia section open to clarify each episode, but in a good way. Winden, a small German town, endures some strange happenings every 27 years that eventually lead to one generation figuring out it’s at the center of a rather large time vortex.
Multiple generations of several families are covered in the large ensemble cast, the three seasons getting bigger as they go, delivering answers that only beg more questions. Baran bo Odar and Jantje Friese’s experiment is prog rock television, and brilliant at that.
9. Battlestar Galactica (2004–2009)
Machines have humans on the brink of extinction, except these people aren’t from Earth, and they’re now trying to find it. Ronald D. Moore’s reboot of the 1978 series transforms a pulpy Star Trek-like into prestige sci-fi that’s unabashedly self-serious and grounded.
Instead of multiple alien races, we have but one, and the robots they built have almost wiped them out. The Galactica’s crew hold no glory, carrying the shared trauma of surviving a nuclear war, led as best as possible by Commander Adama and President Laura Roslin.
8. The X-Files (1993–2018)
UFOs have never had a stronger true believer than agent Fox Mulder (David Duchovny). He and agent Dana Scully’s (Gillian Anderson) fervent discussions about what’s plausible made The X-Files a great engine for strange sci-fi. Episode to episode, they could be up against sentient black goo, or what’s suspected to be an actual gargoyle, or something completely different.
In its early seasons, Chris Carter’s show had the zest of an anthology with the drive of serial drama. Things get shakier from season six on when the conspiracy subsumes all other narrative threads. But when it’s great, it’s truly something else.
7. Futurama (1999–2013)
In the world of tomorrow, we have theme parks on the moon, fully autonomous robots, and the housing market is still dire–go figure. Matt Groening’s 31st-century follow-up to The Simpsons has just as much heart on its sleeve amid the far more aloof and unscrupulous plots and ideas.
Fry, a 20-something that’s been cryogenically frozen for a thousand years, joins Planet Express to deliver parcels around the galaxy. He develops feelings for Leela and spends much of his time hanging with his robot friend Bender or any of his other coworkers. Well-placed emotive beats cultivate a strong fondness for the entire cast, and it has the rare honor of sticking to two disparate endings. Plus, Futurama is back!
6. Babylon 5 (1993–1998)
Well before prestige TV formalized having a set number of seasons, J. Michael Straczynski’s space station drama began and ended as a televisual novel with five installments. Across a five-year timespan, crewmates aboard the titular neutral vessel navigate intense multi-species conflicts and political dilemmas, all the while dealing with personal relationships.
The backdrop is given extra emphasis by being the only constant – when anyone is reassigned, even original lead commander Sinclair, they essentially leave the series, letting us share the loss like actual coworkers. Characters ranking up and moving around complement the extensive lore to make the universe feel alive and worth rewatching again and again.
5. Orphan Black (2013–2017)
In terms of televisual heavy lifting, Tatiana Maslany’s ability to play multiple versions of herself through Orphan Black‘s five seasons is jaw-dropping. When one clone assumes another’s identity, more and more start coming out of the woodwork, leading to a bizarre experiment that’s had global implications.
It’s Maslany’s work that’s the most engaging, her many personalities bouncing off each other without any getting lost in the mix. Graeme Manson and John Fawcett’s mystery isn’t bad either, and it all reaches a satisfying end.
4. Doctor Who (1963–Present)
At nearly 60 years old, Doctor Who, the BBC’s flagship program, has managed to do something right and do it repeatedly. Now 13 lead actors in the Doctor and their TARDIS is a staple of pop culture that’s brought us, and more than a few companions, on some very wild rides.
A timelord, the Doctor can move within time and space like it’s just a load of, well, timey-wimey nonsense. Not every alien encountered enjoys a visit, mind, but most tend to provide memorable stories. The modern iterations, Christopher Eccleston, David Tennant, and Matt Smith, in particular, are perhaps the most widely known, but every generation has its merits. If the many episodes seem like a chore, err toward the crossovers and whatever the last season is, and work outward.
3. For All Mankind
What if, instead of the US landing on the moon, it was the Soviet Union, and what if that created an endless space marathon? For All Mankind answers this hypothetical by mixing Mad Men, Star Trek, and The Astronauts Wives Club into a stylish, hard-science drama about where we’d be if Apollo 11 hadn’t happened.
NASA would have rudimentary colonies in space by the ’70s, adding another icy front to the Cold War. Politics are constant when it comes to sending people to stars above, proving that solving problems up there doesn’t always help what’s down here. This Apple TV show from Ronald D. Moore, Matt Wolpert, and Ben Nedivi handles it all with deft sincerity. Check out our guide on the For All Mankind season 4 release date for more.
2. The Hitchhiker’s Guide to the Galaxy (1981)
In keeping with the perpetual ridiculousness of the radio play and novels, The Hitchhiker’s Guide to the Galaxy became a live-action TV show in 1981, refuting preconceptions that it was somehow unfilmable. Director Alan J. W. Bell translates Douglas Adams’s fantastic, idiosyncratic concepts into a series that’s remarkably easy-going despite starting with the end of the world.
Simon Jones and David Dixon play protagonists Arthur Dent and Ford Prefect, respectively, who are more amicable than you might expect when they suddenly wind up journeying through space on the spaceship the Heart of Gold. Meals at the restaurant at the end of the universe provide all sorts of remedies and a good complement to the eye-catching sets.
1. Firefly (2002)
The fact that it was unceremoniously canceled after a single season makes Firefly’s excellence all the more impressive. Starring Nathan Fillion as Mal, the series is a blend between the Western and sci-fi genres, following a band of renegade space cowboys.
It’s exciting, adventurous, and — most importantly — fun. Perhaps the best thing about Firefly is the dynamic between the cast of characters. They each grow and develop a shocking amount, given that there are only 14 episodes. Because it was so beloved, Firefly was eventually succeeded in 2005 with a movie named Serenity. It’s a good continuation of things, but not as good as its TV origins.
For more sci-fi fun, take a look at our guides to the best science fiction movies and the best movies of all time.