Right now, I'm nearing the end of Ratchet and Clank: Tools of Destruction. However, it may yet be a while because I'm a completionist and I want to collect every gold bolt and hidden goody. But after I finish Ratchet and Clank, I'll start either Skyrim, Saints Row 2 or Mirror's Edge.
Also, those of you who like to check out every single thing in a game would have a hayday with LA Noire.