My Fave are as follows:
1. Mass Effect 2: Love the first one. Story and sci-fi epic feel is the greatest.
2. Killer Instict 3: Shitting my pants for this one
3. God of War 3. The best action game ever!
4. Diablo 3: waiting for ages for this one. Trust me, this one will also be coming out on the 360.
5. Last but not least is Forza 3. Forza 2 was IMO one of the greatest racing game ever and 3 will finally challege GT5.