In my humble opinion, it had to come from the Florida State game: either Leggett's touchdown or the game-winning sack by Boulware and friends.
My vote goes to the touchdown because of the many components that went into making it great. First and foremost was the incredible athletic move Leggett made to leap up and into the end zone, using his off hand to pole vault himself those last few inches. Then there was Watson's composure in spotting the wide open Leggett, who I assume was not the primary receiver on the play, and then to make the feather-soft pass right on the money, in stride, allowing Leggett to make the amazing finish to the play.
But.......
Watch the play again and see FSU's cornerback McFadden (#4) blitzing off the blind side. He actually leaves Mike Williams fairly open, although it appears a safety will rotate over to provide coverage. McFadden seems as if he will make a hard hit on Watson, who does not see him, and if he does, a fumble would seem likely. At the last second, WAYNE GALLMAN slides over and makes a chip block to give Watson time to make the pass. It's not a knock-down, pancake type of block, but it is just enough to make that play happen. If he doesn't make that play, Clemson loses. Just another reason #9 will be one of my all-time favorite Tigers. A great play by a bunch of great players.