All the winning animations are great, but this one in particular stands out to me. The acting and timing is superb. And the style of animation is really interesting - it looks like an intriguing combination of 2D and 3D animation. It reminded me of the finalized footage that I've seen from "Paperman", Disney's new animated short that will play before Wreck-It Ralph.
I do love 3D animation, but I (like everyone else in my generation) have a pretty bad case of nostalgia for the aesthetic of 2D... so to see the two being blended is a very exciting development!
Final note - here's another 11 Second Club winner that really stood out to me - "TV is Power"