8 Most Important Sci-Fi Shows That Define the Genre

Every genre of television has a fascinating history and a long trajectory of some of the medium’s greatest masterpieces, but few genres have ever produced as many groundbreaking shows as science fiction. From classics like Doctor Who to modern gems like Lost, there are several small-screen sci-fi masterpieces which can be counted among the most important shows of their time.

These are all great shows, but they’re far more than just that: They’re also seminal works of science fiction that have helped to define the way the genre looks on television. Whether it’s thanks to their stories, their style, their technical qualities, or their structure, these eight shows are the most important in the history of televisual sci-fi, and all fans of the genre should consider them essential viewing.

‘Doctor Who’ (1963–Present)

Back in 1963, the world was introduced to Doctor Who, a family adventure show about an alien (played by William Hartnell) traveling through time and space with his companions. Originally devised as an educational show aimed at children, the series slowly started to transform into something far more universal. As soon as viewers across the United Kingdom and the rest of the world got to see Hartnell’s First Doctor transform into Patrick Troughton‘s incarnation of the character, the sci-fi game was changed forever.

No matter how one ranks its versions of the Time Lord, there’s no denying that Doctor Who has remained revolutionary throughout its whole run. Aside from its use of regeneration as a plot device perfect for keeping itself fresh, which has made it the longest-running sci-fi show in television history, the show has also constantly been ahead of the curve with its campy tone, imaginative stories, and progressive heart. Doctor Who has far transcended the British television screen and turned into a global pop culture phenomenon like no other.

‘Neon Genesis Evangelion’ (1995–1996)

Image via TV Tokyo

No conversation about anime television or animated science fiction could be complete without at least a mention of Neon Genesis Evangelion. It’s one of the best ’90s anime show masterpieces, an auteur-driven masterwork created by the brilliant Hideaki Anno. The show’s favoring of a slow-paced, philosophically-charged deconstruction of the mecha genre over an action-packed narrative makes it a terrible gateway point for anime beginners, but those already on the medium’s typical wavelength ought to check out Eva at least once in their lives.

On top of helping to popularize anime television globally, Neon Genesis Evangelion is one of the most radically re-defining sci-fi shows in history. Blending sci-fi concepts with surrealism, philosophy, and a slow sense of rhythm, it showed that sci-fi could be the home of more thoughtful and methodically-told stories than audiences were used to. Three decades after its conclusion, watching still feels like you’re experiencing a crucial pillar of the genre.

‘Lost’ (2004–2010)

Image via ABC

From Westworld to Stranger Things to Severance, mystery box shows have been all the rage since around the early 2010s. It was arguably a certain other show that really pioneered the mystery box category, which defines shows featuring large and hyper-complex narratives reliant on underlying mysteries tying it all together. But if there was any show that solidified the mystery box genre as a respectable and hugely popular branch of science fiction, it was Lost.

Jeffrey Lieber, J. J. Abrams, and Damon Lindelof‘s groundbreaking ensemble show immediately proved to be one of the most game-changing sci-fi shows that rewrote genre rules. Whether it did or did not jump the shark in its final season is beside the point here—Lost was a massive pop-cultural phenomenon across the globe during its run, introducing countless people to the potential magic of sci-fi. Virtually every mystery sci-fi show that has been made after 2004 owes something to Lost.

‘Battlestar Galactica’ (2004–2009)

Image via SYFY

There are some sci-fi shows that shouldn’t be remade, and then there are others which beg for a modernization of some kind. The fun-but-dated Battlestar Galactica from the ’70s belonged to the latter group. After an incredible 2003 miniseries, the 2004 revival of the same title didn’t just revitalize and revolutionize the Battlestar franchise—it re-defined modern science fiction as a whole. Here, Dwight Schrute (Rainn Wilson) is to be believed: There’s no science fiction show like this one.

The entire realm of American television took a drastic turn following the tragic events of 9/11, and Battlestar Galactica came as a direct result of that tonal and thematic shift. Suddenly, televisual sci-fi became grittier, more mature, more sharply political, and more morally ambiguous than it had ever been before. By elevating sci-fi into the realm of true prestige television, the 2004 version of Battlestar instantly cemented itself as one of the most important genre shows of the 2000s.

‘The X-Files’ (1993–2018)

Image via FOX

In the history of sci-fi television, there’s before The X-Files and then there’s after The X-Files. With its unprecedentedly large cult following surging right as the worldwide web was starting to be democratized, this Fox gem pioneered the online fandom space. Over three decades after it first aired, it’s still every bit as enjoyable and engaging as it was back in its infancy. Who could have foretold that a sci-fi/supernatural mystery series following a skeptic and a believer could have provided material for over 200 phenomenal episodes that never lost momentum?

From Supernatural to Buffy the Vampire Slayer, virtually every “monster-of-the-week” type of genre show that came after The X-Files was in some way inspired by it. It’s one of those classic sci-fi shows that has aged like fine wine, the show that fully brought science fiction into the modern mainstream television era. Popularizing conspiracy shows (and even conspiracy theories as a whole) and establishing Mulder (David Duchovny) and Scully (Gillian Anderson), the most iconic duo in sci-fi television history, The X-Files left an indelible mark on the history of American television.

‘Star Trek: The Original Series’ (1966–1969)

Image via NBC

Nowadays, the Star Trek franchise doesn’t really need an introduction; but back in 1966, audiences had never seen anything quite like Star Trek: The Original Series. With an unprecedentedly diverse ensemble cast and the distinctly optimistic worldview that has come to characterize the entire franchise, Gene Roddenberry‘s original creation wasn’t huge while it was on their. But following its cancellation, its release into syndication turned it into the gargantuan cult classic that people know it as today.

The Original Series is, in virtually every sense imaginable, one of those sci-fi shows that were way ahead of their time. There’s its cast, its exceptionally progressive politics, its stunning production values, and the uniquely utopian way in which it looks at the future. This lends it infinite rewatchability value even today, as it remains one of fans’ favorite installments in a massive franchise that has no shortage of gems to offer.

‘The Twilight Zone’ (1959–1964)

Image via CBS

Back in the ’50s and ’60s, sci-fi television was in practically no way like what we know today, but Rod Serling was the first person to truly help sci-fi take a leap into modernity. The Twilight Zone is arguably the single most groundbreaking and influential sci-fi TV show in history, and it’s definitely the biggest sci-fi anthology series of all time. Like all anthology shows, it had its fair share of ups and downs; but there’s no way of denying that it completely re-defined televisual science fiction in virtually every sense imaginable.

It’s one of those anthology TV shows that have aged like fine wine, a classic full of iconic episodes that deal with themes that still feel relevant and timely over 60 years after the show’s conclusion. It played an instrumental role in bringing science fiction into the mainstream, proving just how intelligent and culturally relevant the genre could be when in the right creative hands. Sci-fi TV as we know it today could never have existed without The Twilight Zone.

‘Babylon 5’ (1994–1998)

Image via PTEN

Though perhaps not quite as influential, nor nearly as vastly acclaimed as The Twilight Zone, there’s a strong argument to be made that there has never been a science fiction TV show more important or genre-defining than Babylon 5. Almost unprecedentedly for American broadcast television at the time, this space opera was designed as a sort of novel for television, where each season of a pre-planned five-part arc would serve as a different chapter.

Babylon 5 brought not only television sci-fi, but American television as a whole, away from their episodic days and toward a more heavily serialized era. Campy though it may sometimes feel nowadays, it’s nevertheless one of those sci-fi shows that hold up surprisingly well, a game-changing classic without which sci-fi television—and perhaps even American television more generally—would have likely looked vastly different today.