The 13 Best Sci-Fi/Fantasy Season Finales of All Time
Firefly season 1
Watching "Objects in Space" makes us even sadder that Firefly was cancelled so soon, because its last episode was also its best. Taking inspiration from Jean Paul Sartre's existential philosophy, Whedon and co. took the simple plot of a bounty hunter trying to capture River and turned it into a meditation on the pointlessness of human existence, right down to that famous final line from Jubal Early as he literally becomes an object in space, "Well... here I am."
Stargate: Atlantis season 2
The vastly overrated Atlantis was often better than its parent show, and it was nothing if not great at high-stakes cliffhangers. The second season finale, "Allies," was incredibly tense the whole way through, as our heroes negotiated a wary alliance with the nefarious Wraith in an attempt to "cure" several Wraith hives ships and turn them into humans. The ensuing betrayal and battle amounted to one of the most exciting finales we've ever seen, with a rich and complex wrinkly to the mythology as a bonus.
Fringe season 2
Fringe took a while to find its footing, but after the second season, it became one of the best sci-fi shows around, and that's almost entirely due to the developments in the second season finale. "Over There" revealed what became the defining element of the show: parallel universes, as well as Olivia's ruthless counterpart fondly known as Fauxlivia. Fringe was never the same again, and was all the better for it.
The X-Files season 4
"Gethsemane" was a different kind of mythology episode, as it brought the entire mythos of the series into question, from Samantha Mulder's abduction to the existence of aliens and UFO abductions. Of course, we pretty much knew that it would all turn out to be true, and we definitely knew that Mulder didn't really shoot himself in the head, but this was still one of the most mature, well-written developments of the entire show.
Terminator: Sarah Connor Chronicles season 2
TSCC was an extremely mixed bag in its first season, but by the end of the second season, it had finally figured out what worked and what didn't. Like Firefly, its last episode was also its best, and it ended with an amazing cliffhanger that would have done wonders to improve the show. RIP TSCC, at least Lena Headey was immediately cast on another show that made it farther down this list.
Angel season 5
When I first saw Angel's series finale, I was completely let down by the decision to end on a cliffhanger, but now I think it's the best series finale I've ever seen, bar none. After a season of pretty much unmitigated despair, the finale got back to the heart and thesis of the show: it's worth it to keep fighting for what's right, even if you know you can't succeed. Especially then.
The Vampire Diaries season 1
The Vampire Diaries has fallen apart of late, but for its first three seasons, no one did shocking twists quite like this show. The endings to seasons two and three were also excellent, but it never quite reached the heights of the season one finale, the introduction of Katherine Pierce, and the show's first-ever doppelganger mix-up.
The 100 season 2
The 100 started off as a fairly insipid teen dystopian show, but by the fifth episode it had demonstrated that it meant business, and in the second season it proved that it was one of the most thoughtful, philosophical, and socially conscious shows on television. The amazing sophomore season culminated in a tragic season finale that saw the main characters essentially commit an act of genocide, once again demonstrating that this is a show that doesn't pull its punches.
Game of Thrones season 5
Game of Thrones is essentially one WTF moment after another, but the show's finales always find a way to stand out Seeing as we can only pick one, we'd have to say 'Mothers Mercy' was the show's best finale so far. The season 5 finale didn't just leave our jaws on the floor, it also managed to successfully move the show into a whole new era of relative unknowns. Perhaps it was because, overall, season 5 felt subpar, but unlike other season finales Mothers Mercy truly seemed like the standout episode of the entire season.
Battlestar Galactica season 2
It's difficult to pick just one season finale from Battlestar Galactica, and both the Boomer reveal in season one and the "All Along the Watchtower" scene in season three were mind-blowing. But nothing beats season two's "Lay Down Your Burdens," in which a season-long power struggle ends with Baltar being elected president and a flash-foward sequence immediately jumping to a year later, when the Cylons are invading New Caprica (for the record, I was always a Roslin supporter).
Lost season 3
But no one does flash-forwards quite like Lost. This might have been the episode right before Lost started to fall apart a little bit, but "Through the Looking Glass" was chock-full of classic moments, most notable Charlie's death and the ominous message "Not Penny's Boat." And then Lost pulled the ultimate bait-and-switch, and revealed that the flashbacks of the episode were actually flashes of the future, culminating in the now-iconic line, "We have to go back."
Star Wars Rebels season 2
The Season 1 finale of Star Wars Rebels was, at the time, the best episode the show had put out, but 'Twilight of the Apprentice' took everything its predecessor did and more. Ever since Star Wars: Clone Wars was on on our screens, fans had been asking what would happen if Ahsoka Tano came up against her one-time Jedi Master. The season 2 finale answered that with aplomb, but as an episode it was so much more than just a clash of lightsabers. Kanan's injury, Ezra's battle with the dark side, and the return of Darth Maul all combined to make this one of the most memorable moments in Star Wars history.
Buffy season 2
It was a tough choice between "Becoming pt 2" and "The Gift," but this was the episode that made every Buffy fan cry (if you have a heart, at least). Angelus was by far the most gut-wrenching villain Buffy ever had, and Buffy's decision to sacrifice the person she loved to save the world made for a tragic but satisfying conclusion and a nearly perfect season finale.