TF2, MW2, JK:JA (found it lying around), a bit of W3 and DOTA , GMod when I'm bored and hoping to get HON when it's released...stupid friends didn't get me a key...
Oh, and should get Bad Company 2 later in the year.
Nikokapo, what's your steam name? I'll have to play you some time.
EDIT: Almost forgot to mention Legend of Zelda: Ocarina of Time (one of THE BEST games ever!), Forced Unleashed, Jedi Academy, Knights of the Old Republic (absolutely brilliant!), HL2, Legend of Zelda: Twilight Princess.