I wouldn't be too surprised if it was Boom Blox Bash Party. The first one was high 80's, I think 85 on Metacritic, and if the sequel improves exponentially, as I have faith it will, I think it could crack that barrier.
Madworld also has a shot if the game holds up as the previews have already praised it.
My Games of 2011:
The Legend of Zelda: Skyward Sword
Elder Scrolls V: Skyrim
Super Mario 3D Land
Uncharted 3: Drake's Deception