Planescape Torment is a darn classic! Other than that it's all about
Diablo 2,
Fallout series (though I'm still not sure what to think about the third part),
Baldur's Gate,
Heroes 3,
Assasin's Creed (gimme the new one NOW!!!) and some recent RPGs such as
The Witcher and
Dragon Age Origins. Just finished with its expansion
Awakening - nice job on it, though the ending should've been more epic as on the game itself, maybe. I also enjoy some adventures like
Syberia,
Art Of Murder,
Memento Mori, good old
Black Mirror and the sort when I want something different. Can't leave out
Crysis,
Death Space,
S.T.A.L.K.E.R. and
Metro 2033 which I finished about some days ago, too - good thing it also follows the plot of the book, the atmosphere is one of a kind!
...Wowz, I almost missed the EPIC
Left4Dead parts!