Counting Down the 10 Greatest Sci-Fi TV Series Ever

The Golden Age of TV has offered plenty of sci-fi TV series, which is great: the high production quality that has marked the shows of this era looks beautiful when applied to sci-fi in series like Westworld. Of course, science fiction has a long history of iconic shows and cult classics, so balancing the fancy newcomers against the shoestring-budget oldies is a tough thing to do. The classics largely win out in the list that follows (albeit with one notable exception and a few ordering choices that are sure to earn me some ALL-CAPS EMAILS), but Black Mirror gets the nod here in part because it feels like it’s in conversation with that past as it mixes The Twilight Zone’s eerie anthology vibe with a very modern feeling of tech-induced paranoia.

All five seasons of this consistently surprising series are currently available to stream on Netflix. Since each episode stands alone, there's no need to watch in order. For a curated taste of what Black Mirror has to offer, check out our list of the best—and most sci-fi heavy—episodes.

Doctor Who is, of course, a classic: the good Doctor and their time-traveling police box-spaceship have made it through over 800 episodes, and the show is the longest-running sci-fi TV series of all time (albeit not consecutively). Doctor Who can be strange, charming, and silly, but it also knows how to pull off an action sequence or tug on the heartstrings (the Tenth Doctor's regeneration, anyone?).

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The X-Files managed to make the jump from cult hit to pop culture classic. It rose from humble beginnings but became bankable enough to spawn movies and, recently, a return to the small screen. It’s a fascinating sci-fi TV series to re-watch now in part because it still seems to have a divided soul. The X-Files features standalone episodes that are underpinned by a long-running series plot. Its special effects seem cheesy at times and excellent at others. It invented its own tropes and then indulged them. 

A major part of the series' appeal, at least for many ardent shippers, is the chemistry between David Duchovny as Fox Mulder and Gillian Anderson as Dana Scully. Despite—or perhaps because—of some initial off-screen tension between the two leads, Mulder and Scully have undeniable intensity together from the first episode. Creator Chris Carter recognized that chemistry, and leaned into the ambiguous heat between the two FBI agents. In between the monster of the week episodes and the more overarching mythology of the series, there's also plenty of scenes that tease fans' desire for the two to get together. 

The X-Files is a major-network hit and a cult classic at once, but it's indispensable either way.

RELATED: 14 of the Best X-Files Episodes of All Time

As Wayne Campbell once said, Star Trek: The Next Generation is “in many ways … superior, but will never be as recognized as the original.” Well said, Wayne. Star Trek’s best spin-off series features better special effects, more thoughtful plots, and superior acting. It’s not as revolutionary as its older counterpart, but it is arguably more fun to watch, and it still ranks among the most iconic sci-fi TV series of all time.

Futurama wasn’t necessarily revolutionary, but it did everything well. It poked fun at familiar tropes while feeling fairly familiar itself. It was a hi-fi Simpsons with a loveable sitcom cast. It was funny, but not paralyzingly so, and emotional, but not disturbingly so. It was, simply, a really good series: the kind of show you can watch almost anywhere and at almost any time and just enjoy. You can’t swing a stick without hitting someone who doesn’t like Rick and Morty, but you will have a hard time finding anyone who doesn’t tolerate Futurama; though, if you did, you probably would want to hit them with that stick.

Part of Futurama's likability might be that it's not afraid to sincerely explore some of the disturbing questions raised by the show's sci-fi setting: For example, if you take a millennium-long cryogenic nap, what happens to your friends and family who are left awake? What would the inevitable downslides of time-slipping into an 'ideal' marriage be? During its run(s), Futurama explored these questions with a charming balance of sincerity and snark, all while paying delightful homage to classic science fiction. 

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There’s a parallel universe somewhere where Stranger Things went as unheeded as everyone expected it to, where it’s a cult classic and where Firefly-style super-fans beg for it to come back. But our universe has the internet, Netflix, and the Golden Age of Television, and Stranger Things became a word-of-mouth hit and then a viral phenomenon. Stranger Things’ second season had strong moments and interesting themes, but it’s the improbably perfect first season that lands the show on our list of the greatest sci-fi TV series of all time. 

Stranger Things arrived fully formed, feeling nostalgic and new at the same time. To watch the first season for the first time is to feel at times like you’re re-watching an old favorite and, at other times, like you’ve never seen anything like this before. If you haven't visited Hawkins, Indiana yet, grab some Eggos and prepare for your world to be turned upside down. 

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We’re talking the 2004 revival here, which is really the gold standard for sci-fi TV series reboots. Battlestar Galactica’s story follows human refugees on the run from the Cylons, who–in the reboot’s much-improved imagining–are machines that can look nearly perfectly human. 

For the reboot, producer Ronald D. Moore genderswapped two significant characters from the original 1978 Battlestar. The female incarnation of Starbuck—played to perfection by Katee Sackhoff—is a compelling, flawed, kick-ass character, whose exploits both in war and love continue to thrill fans. The reboot's four seasons (and a made-for-TV-movie) explored compelling questions about religion, power, and what it means to be human. Also, this is the show that used “frak” as a profanity. What more could you frakking want? 

Before Black Mirror there was The Twilight Zone, the anthology sci-fi TV series that subverted expectations and delighted in twist endings and startling reveals. Nearly 70 years after its debut, The Twilight Zone feels more like an icon than a relic: it defined its genre so totally that choices that should be dated instead feel entirely appropriate.

Firefly is the perfect cult-hit sci-fi TV series. Its premature cancellation left it frozen in time, and it works as much because of that as despite it. Firefly is flawed in all kinds of ways, but like the best cult shows, those flaws somehow feel structural, as if the whole thing would fall apart without them. I’m not saying that Firefly couldn’t have kept this tightrope act up for another season or 10, or that it couldn’t have become the all-time greatest sci-fi TV series that its fans believe would have been. But I am saying that its first season is a fascinating one to have frozen in amber, and that Firefly is the best TV cult classic in a genre full of them. That’s no mean feat. 

If you're not familiar with Captain Tight Pants and his motley crew of Browncoats yet, settle in for its single, seminal season—then stream the 2005 follow-up movie Serenity.  

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No single show had a greater impact on the future of sci-fi television–and science fiction in general–than Star Trek. Gene Roddenberry was inspired to create his 1960s space adventure series in part by the Horatio Hornblower series of maritime novels, which makes a lot more sense when you remember that he couldn’t have drawn inspiration from the show he was about to invent, which is what just about everyone else has done since.

Star Trek really does feel like the prototype for almost every sci-fi TV series that came after it. It’s every kind of sci-fi franchise at once. It’s a pop culture touchstone, but one with cultish die-hard fans; it’s an underappreciated gem cancelled just three seasons in, but also the starting point of a multimedia empire of movies, novels, toys, and spin-offs. More than 50 years after it first aired, Star Trek would be required viewing even if it wasn’t still a ton of fun to watch. But it is.

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