I'm not really sure I remember all the games I've played this decade. Anyway, I haven't played a whole lot of super awful games, but I've had some nice letdowns. That said, those letdowns include Spore (overhyped), Force Unleashed (I don't think I could have done much better myself, but I expected to feel a lot more powerful.), and Fallout 3 (Ooh Bethesda! They did Oblivion, and I really liked that! Oh, wow, there aren't nearly as many side quests as I thought. And my skills don't go up with use, just with levels. Oh, and a super low level cap.)
Edit: And Lair. It was nearly unplayable sometimes because of how finicky the sixaxis controls could be. (Oh, you want to dash? How about a 180 flip instead. Oh, NOW you want to do that 180 flip? Try this dash instead.)
EDIT: And Lair. The sixaxis controls on that game drove me crazy. It seemed to have a lot of trouble telling the difference between a dash and a 180...And up and down...And left and right.