Few entertainment products are as satisfying as a good time loops, and other staples of the genre are all a device to explore the true nature of humanity. Every good story, after all, is about what it means to be human in one way or another.

There are several elements that work together to make a good sci-fi show beyond the bizarre ships and unique worlds, like visual effects to acting performances. Audiences need to believe that what they are seeing is really happening in space, on a mysterious deserted island, or wherever else a story might be set. The most important element of them all, though, is a good script. A good script can save a show where all the other technical aspects might not be as excellent, while the opposite is rarely true.

10 Lost (2004-2010)

Number Of Seasons: Six

The broad scope of wild twists of Lost would have fallen apart if it weren't for the strong writing found throughout the show. Lost is not sci-fi in the most classical of , since the show's events don’t happen somewhere off in remote space. Instead, it's set on a deserted island where the main cast of characters crash after a plane incident. Still, Lost’s mysterious narrative, filled with questions, puzzles, and plot twists, makes it a perfect fit in the sci-fi genre.

Lost is a monumental piece of television, often hailed as one of the best shows to ever have been produced. It definitely marked a watershed moment in the history of this particular medium. That is still true even when taking Lost's finale into consideration, which has instead raised some eyebrows when it was first aired and didn’t exactly meet fans’ expectations. Still, Lost remains one of the best-written sci-fi shows out there, one whose writing has inspired its fair number of emulators.

9 Andor (2022-ongoing)

Number Of Seasons: One

Andor is hands down the best Lucasfilm show has produced since its acquisition by Disney. The first seasons of The Mandalorian — another beloved Lucasfilm show — were a fun western-like adventure, but Andor is a perfect fit in the greater Star Wars canon, bridging bridges the gap between the Prequel Trilogy and the Original Trilogy. The show reeals to audiences how the Rebel Alliance was born and just how much sacrifice was needed to do that.

Andor’s script doesn’t shy away from the most brutal parts of the Empire’s rule of the galaxy, really taking the “wars” in Star Wars to heart. Its dialogues and monologues — the best of which are delivered in the final episode by Stellan Skarsgård’s Luthen Rael and Fiona Shaw’s Maarva Andor — dive down into what it means to live under a totalitarian regime and decide to give up everything to fight it. It's a compelling, mature, and morally murky show that delivers on the premise.

8 Battlestar Galactica (2003-2009)

Number Of Seasons: Four (And One Miniseries)

The Battlestar Galactica that most people know and love is a re-imagining of the 1978 show of the same name, with more or less the same premise. In the most classic of sci-fi traditions, Battlestar Galactica is set in a distant future where humans have moved away from the Solar System and are now embroiled in a long war with an android species known as the Cyclons. What separates the 21st-century version of Battlestar Galactica from other shows is the way it explores a desperate humanity on the edge of oblivion.

Battlestar Galactica has been praised far and wide ever since its release. Across a miniseries and subsequent four seasons, the show received accolades for pretty much every aspect of its production from visual effects to sound editing to, of course, writing. The intricacies of the lives of the crew of the titular Battlestar Galactica ship in the wake of a devastating Cyclons attack are once more proof that all sci-fi is actually about humanity, no matter how far off in space and time it’s set.

7 Babylon 5 (1993-1998)

Number Of Seasons: Five

Another staple of television sci-fi, Babylon 5 follows a cast of characters that live on the titular space station Babylon 5, meant as neutral, diplomatic ground after a series of devastating inter-species wars. As the story progresses, Babylon 5’s main characters all have to deal with their personal problems and relationships. This is on top of their roles in galactic conflicts that are ravaging their respective worlds.

What made Babylon 5 unique at the time of its airing is also what has made it withstand the test of time and remain a beloved sci-fi product even to this day — and that’s the coherence of its plot. The show was meant to have five seasons ever since its ideation. The story stretches across those five seasons incredibly well, with each episode being directly connected to the ones before and after rather than being somewhat auto-conclusive. This was a then-unique approach to episodic television that has become the standard in modern shows.

6 The X-Files (1993-2018)

Number Of Seasons: Eleven

The X-Files is another show that left its undeniable mark on the history of television. While not classic sci-fi set on far-off planets or with technologically advanced spaceships, it still deals with plenty of paranormal themes. The story follows pop culture icons Fox Mulder and Dana Scully, two FBI Special Agents who deal with the titular X-Files. These unsolved cases all have to do with the supernatural.

In its years-long run, The X-Files helped popularize the pattern that is now everywhere on television, the “monster of the week”— with Mulder and Scully dealing with a different case in each episode. On top of that, the show does have an over-arching plot that deals with the threat of an alien invasion. As sometimes happens with long-running shows, The X-Files’ ending left some fans unsatisfied, but the show still remains a pillar of the sci-fi genre.

5 Severance (2022-ongoing)

Number Of Seasons: Two

Severance is a recent release and yet one that managed to garner incredible success in the short time it has been available for streaming. Severance is also not exactly classic sci-fi, but the absence of laser guns and aliens doesn’t make its story any less entertaining — or any less relevant to the current cultural moment. This is another thing sci-fi is usually very good at tapping into, and Severance does a phenomenal job of it.

When Severance premiered in 2022, it was unlike anything else on television. From its meticulous production design to its mystery box plot, it was a series that felt firmly of its time in its exploration of labor and workplace misery while having the vibe of a delicious throwback thanks to its mid-century modern look and the timeless quality of its central conceit. - Graeme Guttmann - ScreenRant's Severance review

Severance's story follows a group of employees of a fictional cult-like corporation that have agreed to be “severed,” meaning that their work memories are separated from their personal ones. After this process, they develop a double personality — the “Innie” is the one that works at the corporation while the “Outie” is the one that lives their everyday lives. Severance’s unique and brilliantly written story helps make it the incredible show that it is, together with excellent performances from pretty much every member of its cast.

4 The Expanse (2015-2018)

Number Of Seasons: Six

The Expanse is one of the best examples of classic-style sci-fi made in recent times. Based on the book series of the same name by James S. Corey, the story is set in a not-so-distant future where humanity has colonized a good chunk of the Solar System —and where the conflicts that have always happened between nations are now blown up on an interplanetary scale and taking place between Earth, Mars, and the Asteroid Belt. Even moving to the stats can't keep people from being people, in the best and worst ways alike.

The Expanse’s story is fast-paced and filled with twists and turns as the show’s main characters realize just how big the conspiracy that they’ve found themselves embroiled in really is. It’s the kind of show that keeps its audience guessing, working over each new piece of information to try and guess how the events will move forward. It does this without spoon-feeding everything to them, which makes for an incredibly entertaining time.

3 Star Trek: The Original Series (1966-1969)

Number Of Seasons: Three

There would be no sci-fi as we know it today without Star Trek, a pillar of pop culture and a cult classic of the genre. The show was created by Gene Roddenberry, which then spawned a massive media franchise that is still going strong to this day. Years before it became a cultural phenomenon and the basis for so much of what is considered staples of the sci-fi genre, it was just a really good show that still holds up.

That’s ultimately what makes Star Trek one of the best sci-fi shows to have ever been produced. The adventures that the crew of the USS Enterprise, including Captain Kirk, First Officer Spock, Doctor Bones, and Communications Officer Uhura, embark on are compelling. Each episode of The Original Series is incredibly entertaining if a bit goofy. They also provide ample commentary on society in the Sixties that can still be taken to heart to this day.

2 Dark (2017-2020)

Number Of Seasons: Three

Obscure and complex, Dark was quite the phenomenon when it was first released to streaming audiences as Netflix’s first German-language original series. Five years after it first aired, it remains one of the most engaging and thrilling pieces of sci-fi narrative to hit television in recent years. The story follows the lives of the citizens of a small German town as they get disrupted by the disappearance of a child.

Further investigations on said disappearance reveal a generations-long conspiracy that relies on time travel, possible thanks to a wormhole hidden under the forest just outside the town’s borders. What’s most appealing about Dark is that it trusts its audience to follow along with its quite complicated plot as it ebbs and flows through time. There is zero script space wasted in big recaps to remind everyone what has happened.

1 The Twilight Zone (1959-1964)

Number Of Seasons: Five

It’s not any day that a show’s name becomes a commonly used expression to indicate something that regularly happens in said show. However, that's exactly the case with Rod Serling's The Twilight Zone. The fact that “twilight zone” is now used to describe experiences that seem surreal or supernatural should be enough to testify to just how monumental this show is and how expansive that concept proved to be.

An anthology series, each episode consisted of its own self-contained plot. The Twilight Zone is a collection of stories that deal with disturbing, unusual, at times even paranormal events. Most episodes feature a similar narrative structure, which includes a plot twist towards the end and some sort of fable-like moral. While several of its episodes can be categorized as fantasy or horror, The Twilight Zone remains a sci-fi show first and foremost and one of the very first iterations of the genre to make it on mainstream television.