Rainbird on 09 February 2010
I really can't narrow it down based on my enjoyment alone and be satisfied.
But for the sake of answering, I'll go with Guild Wars. I spent a lot of quality time in there, and I can't wait to play Guild Wars 2!
And Vampire: The Masquerade: Bloodlines is a great game! 
Other games I'd consider for the title would probably be KoTOR, MGS4... I can't point any others out now, but they are there 
