io9's March TV Madness: Doctor Who vs. Star Trek: TNG! Buffy vs. Firefly!S

Which science fiction classic will our second Final Four match-up to take on the original Star Trek, in our March TV Madness championship? Will it be the show's much-lauded, long-running successor Star Trek: The Next Generation? Or will it be the beloved, ludicrously long-running British behemoth that is Doctor Who? The choice is yours! Plus decide the winner of the Whedon Invitational Tournament, as Buffy the Vampire Slayer faces off against Firefly!

You can find the polls down below; voting will be open until midnight Pacific time tonight, so make your voice heard now! Today is our second Final Four match-up and the W.I.T. championship. On Friday, March 29, we wrap up this year's March TV Madness with the final championship showdown. The original Star Trek has already clinched a spot, and now it's up to you to choose its worthy opponent. To see how we reached this point, check out the bracket below. You can also click right here for a closer look.

io9's March TV Madness: Doctor Who vs. Star Trek: TNG! Buffy vs. Firefly!S

There's also the Whedon Invitational Tournament, in which Joss Whedon's four TV shows were pitted against one another. Unsurprisingly, Buffy the Vampire Slayer and Firefly routed Dollhouse and Angel in the semifinal round, setting up what should be a hell of a match-up in the championship. Here's the updated W.I.T. bracket; again, click here for an even bigger view.

io9's March TV Madness: Doctor Who vs. Star Trek: TNG! Buffy vs. Firefly!S

Both Doctor Who and Star Trek: The Next Generation have taken down some worthy opponents to reach this point, particularly in the Elite Eight round. Doctor Who fought off an impressive challenge from the Battlestar Galactica reboot, while The Next Generation sprang the minor upset by defeating the venerable Twilight Zone. Those match-ups were the first time either show had really been tested; before that, the shows romped past the likes of Babylon 5 and Lost without ever getting less than 75% of the vote. We'll see how this plays out, but this could be one of the closest match-ups of the entire tournament, making Star Trek's 62%-38% triumph over The X-Files look easy by comparison.

But enough talk from me — it's time for you to vote. Decide the fate of Doctor Who and Star Trek: The Next Generation, then decide which show is the most Whedon of all in the showdown between Buffy the Vampire Slayer and Firefly. Polls are open until midnight Pacific time tonight, so vote now!

March TV Madness Semifinal

The Whedon Invitational Tournament Championship