In order, counting down:
10. Guitar Hero II
9. Marvel Ultimate Alliance
8. Gears of War
7. Soul Calibur IV
6. Gears of War 2
5. Call of Duty 4: Modern Warfare
4. Resident Evil 5
3. Halo 3
2. Halo Wars (There don't seem to be a lot of fans of this game here and I’m not sure why)
1. Street Fighter IV (One of the better fighting games I've played in a long time)
To be fair, though, I have a lot of great games (Mass Effect, Bioshock, The Orange Box, Grand Theft Auto IV, Rock Band 2, Crackdown, Tales of Vesperia) in my backlog, still sealed, that I haven’t got to playing yet, due to having a 1 year-old and being a neurotic game completist before I move on to the next game. I’m sure when I pick up Halo 3: ODST this September and Fallout 3 GoTY edition this October, they’ll both take spots in the top 10.