Portal 2, Skyrim and Bastion, respectively (and respectfully). Supergiant is nominated for Best Debut, alongside Team Bondi for L.A. Noire and BioWare Austin for Star Wars: The Old Republic.
Batman: Arkham City, Skyrim, Portal 2, Deus Ex: Human Revolution and Dark Souls are nominated for Game of the Year. The awards ceremony will be held on March 7. We're not going to say that the GDCA stole their entire list of nominees from a super-cool and highly regarded gaming website, but it does look familiar: