It’s insanely difficult to maintain outstanding quality throughout a long-running sci-fi program. From amazing anthology series to underappreciated cult favorites, the history of sci-fi TV is full of shows that boasted perfect seasons.

While many of the best perfect episodes.

10 The X-Files (1993 - 2002, 2016 - 2018)

The X-Files season 3 was a perfect 10/10

The X-Files was a truly trailblazing sci-fi series and one of the defining TV shows of the 1990s, although even hardcore fans will it that some seasons were better than others. With an astounding 218 episodes and various spin-off media, it would be practically impossible to maintain peak quality throughout, although season 3 came as close to perfect as the show ever got. With the perfect blend of serialized storytelling and classic monster-of-the-week episodes, this season made the most of its carefully built lore, emphasizing romantic and humorous stories alongside hard sci-fi concepts.

By its third season, audiences understood what to expect from The X-Files, and it was able to delve even deeper into its rich mythology. With episodes laying the groundwork for the viral alien black oil, the First Elder, and the mystery surrounding X, there were just so many examples of the show embracing complexity while delivering hugely entertaining episodes. With five Emmy wins, The X-Files' third season highlighted the series truly hitting its stride.

9 Black Mirror (2011 - Present)

Black Mirror season 3 was a perfect 10/10

The British anthology series Black Mirror was telling incredibly bleak and thought-provoking sci-fi stories from the very beginning, although in its first two seasons, the show was produced by Channel 4 before moving to Netflix after the grim holiday special “White Christmas.” With this move to streaming, Black Mirror gained a much larger budget, leading to many of its greatest episodes. From classic imagined dystopias like in “Nosedive” to the oddly poignant "San Junipero,” season 3 was the point where Black Mirror grew from an underappreciated sci-fi favorite to a truly global phenomenon.

The third season of Black Mirror featured some of its creator Charlie Brooker’s best writing as he balanced gut-wrenching intensity with some small glimmers of hope. As a glimpse into the darkest versions of our imagined future, Black Mirror has always showcased the way technology has been both a blessing and a curse to society. While later seasons of the show had hit-and-miss episodes, season 3 was 10/10 the whole way through.

8 The OA (2016 - 2019)

The OA season 1 was a perfect 10/10

The OA was the greatest Netflix series that nobody watched, and it was sadly axed by streaming after just two seasons and a major cliffhanger. While season 2 had plenty of intriguing moments, the truth was that the show was never better than its intriguing first season. Telling the story of a mysterious missing blind woman who resurfaces after having been missing for seven years with her sight restored, this fascinating series blended fantasy, sci-fi, and the supernatural.

Co-created by and starring Brit Marling as Prairie Johnson, the young woman also known as the titular OA, this thought-provoking series saw its star find connection with a group of misfits as she revealed her connection to another dimension. As a thematically rich and challenging series, it’s a real shame that The OA wasn’t able to finish its run, although sci-fi fans can go back and watch this woefully underseen series and the litany of viewers who were disappointed by its cancellation, with one fan going on hunger strike outside Netflix’s headquarters (via Vanity Fair) demanding its return.

7 Fringe (2008 - 2013)

Fringe season 3 was a perfect 10/10

Fringe was truly one of the most enthralling and bingeable sci-fi series of all time, which rarely gets its due as one of the best procedural series ever. With explorations of time travel, alternate universes, and high-concept sci-fi themes, while Fringe was great from the beginning, the show achieved a perfect season as it began to focus on season-long arcs and serialized storytelling. With season 3 representing the show at its peak, this amazing piece of television ensured that practically everything that had built up over the first two seasons at last paid off.

With the parallel universe Fringe Division coming to the forefront as major protagonists, Fringe season 3 pushed these characters into the forefront rather than as simple villains. With viewers already familiar with the complexities of this show’s mythology, Fringe was able to explore the story of two worlds going to war with one another.

6 Westworld (2016 - 2022)

Westworld season 1 was a perfect 10/10

While the later seasons of Westworld continued to explore intriguing sci-fi concepts, if the show had been a one-season miniseries, it would have gone down in history as one of the greatest science fiction stories ever told. As a powerful exploration of artificial intelligence, technology, and the destructive consequences of entertainment, Westworld’s first season encouraged viewers to watch carefully and search for clues to unpack its carefully constructed mystery. With a twist involving multiple connected timelines, the appeal of Westworld’s premiere season was that even though it was complex, it never felt alienating.

However, Westworld lost its way in its later seasons as it introduced new concepts and stayed ever further from the Wild West amusement theme park setting. While later installments maintained the show’s stellar writing and complex storytelling, it started to pack too many ideas into its episodes, and the show began crumbling under the weight of its own ambition. Sadly, by the end of the show’s run, many viewers had dropped off, and most were disappointed it could not maintain the creative heights of the show’s glory days.

5 Stranger Things (2016 - Present)

Stranger Things season 1 was a perfect 10/10

It’s truly hard to understate just how much of a big deal it was when the first season of Stranger Things aired back in 2016. As a nostalgic callback to the aesthetic of the 1980s, Spielbergian sentimentality, and Lovecraftian horror, this exciting new series updated an older style for a new generation and was elevated by the skills of its immensely talented young cast. With familiar faces like Winona Ryder also adding to the nostalgic feeling of the show, Stranger Things season one just delivered on all fronts.

While later seasons of Stranger Things remains essential viewing for sci-fi fans worldwide, it’s still the first season that contained many of the show’s most iconic moments. From Eleven’s father-daughter relationship with Hopper, the friendship she developed with Mike and the rest of the gang, and the residents of Hawkins' first encounters with the Upside Down, Stranger Things immediately signalled itself as a modern classic. While it’s hoped the long-awaited final season will also be a 10/10 season, for now, season 1 remains the show at its peak.

4 Futurama (1999 - Present)

Futurama season 4 was a perfect 10/10

While Futurama was always a fantastic animated sci-fi series, its impact is sometimes overshadowed by the cultural dominance of another Matt Groening-created show, The Simpsons. However, this was a real shame because in many ways Futurama actually sured The Simpsons in of storytelling, clever writing packed with physics and mathematical humor, and a real sense of sentimentality. Futurama really hit its stride in season 4 with a run of episodes that were absolutely perfect.

Not only did Futurama’s fourth season deepen the series lore and add depth to the characterization of Fry and the rest of the Planet Express crew, but it also featured the most gut-punching episode of the entire show. Any viewers who have seen it will not be able to forget “Jurassic Bark,” the heartbreaking episode that told the story of the dog Seymour, who, unbeknownst to Fry, spent the last days of his life faithfully waiting outside Panucci's Pizza for his owner's return that would never come to be. Just thinking about it makes us tear up a little.

3 Doctor Who (2005 - Present)

Doctor Who season 4 was a perfect 10/10

The adventures of Doctor Who date all the way back to 1963, and this universe-traversing Time Lord was reintroduced to modern viewers when the series was revived back in 2005. While the first season with Christopher Eccleston as the Doctor kickstarted the revival with a bang, things got really interesting after David Tennant took up the role in the second season. Tennant’s run as the Tenth Doctor lasted three seasons, and it was in season four where everything came together absolutely perfectly, and the sci-fi series delivered a perfect 10/10 season.

Everything about season four of Doctor Who just worked as Catherine Tate blew all expectations out of the water as the beloved companion Donna Noble. With showrunner Russell T. Davies managing to blend the campy fun of “Partners in Crime,” the philosophical horror of “Midnight,” and the all-out war of the two-part finale “The Stolen Earth/Journey’s End,” this season featured just about everything a sci-fi TV lover could possibly ask for.

2 Heroes (2006 - 2010)

Heroes season 1 was a perfect 10/10

Coming out two full years before the beginning of the Marvel Cinematic Universe, Heroes was an NBC drama that showcased the potential of superhero stories on the small screen. With an astounding debut season, the first 23 episodes of Heroes was a perfect 10/10 run that had viewers immediately hooked on its “save the cheerleader, save the world.” With mature storytelling and an engaging ensemble cast of characters, Heroes was a show whose premise of everyday people developing superpowers provided practically unlimited opportunity for compelling storytelling.

While the first season of Heroes signaled the series as one of the most exciting shows on television, everything fell apart in season 2. As one of the most notorious victims of the 2007–2008 Writers Guild of America Strike, the planned 24-episode second season was cut to just 11, and these production problems meant the show lost its momentum and never regained it. While there have been several attempts to tap into the jaw-dropping power of Heroes season one with revivals like Heroes Reborn in the years since, nothing has ever come close to that all-time opening season.

1 Lost (2004 - 2010)

Lost season 1 was a perfect 10/10

From its all-time great pilot episode right through to the fascinating truth behind the mysterious island, few shows have managed to hook viewers in quite like the first season of Lost. As a cryptic mystery box series that mastered the art of cliffhangers at the end of almost every episode, Lost always offered just enough information to leave viewers begging for more and eagerly tuning into the next episode. With great characters and a flashback structure, Lost was the most talked-about TV show in the world back in 2004.

Telling the story of the survivors of Oceanic Airlines Flight 815, Lost blended sci-fi with the supernatural and walked the fine line between fantasy and reality. As a sci-fi series where anything was possible, Lost took cues from serialized mysteries like Twin Peaks to carve out a mythology that had viewers endlessly discussing their theories. Sadly, Lost was not a 10/10 show for its entire run, and it felt like by the end it had overpromised and underdelivered, but it’s about the journey and not the destination, and season one was truly a wild ride.

Source: Vanity Fair