The Orange Box - 360 - Portal is awesome, if a bit short. The Strider attack in HL: Episode 2 was the most fun I've had in ages. Like the commentary feature on most games. Team Fortress 2? More deathmatching? *yawns*
Oblivion - Morrowind all over again, with a new world to explore and prettier graphics, which is a good thing. Much harder to rob everyone blind than in Elder Scrolls III, which (rightfully so) ads to the challenge. Really makes me salivate for Fallout 3, of which I just pre-ordered the collector's edition (cuz everybody loves bobble heads.)
Also bought DL points for Rez HD, a lovely, lovely little trance game, and Geometry Wars, which I somewhat regret because it lacks the deep customization options that you get in Grid Wars 2 for free. Strange that a user created clone would be better than the original, but that's the case here.