i'm not surprised at all. It's the most unique game out of the list that brought something very refreshing to consumers.
It was also named best next-gen game by some other publication.
I forgot who it was...but some other publication gave it 11/10? lol.
CoD4 wasn't that great of a game. 7/10 at best. Just another FPS
I haven't played World in Conflict.. Just another RTS (as for RTS, Company of Heroes is quite possibly the best ever IMO)
Bioshock, although very good, is just yet another fps.
Crysis, looks ultimate awesome, but unfortunately no computer in the world can even run it so why bother...and, it's still another fps..
The Orange Box is great fun, but yet again..it's just another multiplayer FPS (although portal is extremely unique)
Rockband...hmmm, rockband should be co-winner for sure.
Halo 3. umm. NO.
Forza 2. great for race fans..nothing more.
Just saying that all these genres really do not offer anything groundbreakingly new (except for orange box and rockband)