I always wait at least a year before I buy games, so I can't really say. I have played Spore, which I know a lot of people like, but it didn't really do much for me - and I usually like those types of games. And up until I read this thread, the one I was most looking forward to playing was GTA4. I'm surprised to see all the positive feedback for Left For Dead though. As a major fan of Resident Evil 4, it looks like it might be up my alley. I'll likely get both of those games, along with Call of Duty 4, once the price drops out of the $50 range. Until then, I'm perfectly content with the Command & Conquer complete set that I got for Christmas, and Silent Hill 3, which I haven't started yet.
As far as '09, I'm really looking forward to The Sims 3.