(Photo by John P. Johnson/HBO; Frank Ockenfels/FOX; SyFy; Netflix)

100 BEST SCI-FI TV SHOWS OF ALL TIME

Science fiction is often celebrated as a forward-thinking genre that promotes peace among all life forms. But deciding which sci-fi TV series is the best? That debate could start an intergalactic war.

To determine which series is the supreme ruler of the sci-fi genre, we took into consideration Tomatometer data culled from critics’ reviews, plus a number of reputable “best of” lists, and sprinkled the effort with some editorial discretion, asking ourselves which shows have stood the test of time, inspired spin-offs and copycats, and even made their influence known on the big screen.

Some usual suspects naturally came out on top: Doctor Who, Fringe, Firefly, Orphan Black, and creator Ronald D. Moore’s mid-2000s re-imagining of Battlestar Galactica received high marks across the board — not surprising, since they all also have high Tomatometer scores, as do relative newcomers like Westworld, The Expanse, and Black Mirror.

One of the toughest calls we had to make was what exactly constitutes science fiction. Fantasy, mystery, horror, and postapocalyptic genres can appear to enter the sci-fi realm, but we had to create some boundaries. David Lynch and Mark Frost’s Twin Peaks, which famously popularized the dead-girl murder-mystery trope before dovetailing into something more complicated, was deemed horror-fantasy (so don’t bother “Where’s Twin Peaks?!”–ing us in the comments). What about shows in the Marvel Cinematic Universe like Jessica Jones and Agents of S.H.I.E.L.D.? Superhero shows were deemed a separate category.

Ranking each of these shows is a Gorn wrestling match all its own – especially when it comes to now-classic titles whose scores are so Rotten, they threaten to stink up the whole list. Have fond memories of 1979’s Buck Rogers in the 25th Century? Hate to ruin any childhood reverie, but it stands at a ripe 33% with 15 reviews on season 1. It still makes the list because of its nostalgia value and the relatively low number of reviews available.

Disagree with our ranking of the best sci-fi TV series? Tell us about your favorites in the comments!

Best Sci-Fi Series

100-81 | 80-61 | 60-41 | 40-21 | 20-1

Best Sci-Fi Series

100-81 | 80-61 | 60-41 | 40-21 | 20-1