If I had to go with ten:

1. Smash Brothers Brawl
2. Resident Evil 4
3. Metroid Prime 3
4. Mario Galaxy
5. Bully: Scolarship Edition
6. Twilight Princess
7. Super Paper Mario
8. Medal of Honor: Heroes 2
9. No More Heroes
10. Red Steel

Honorable Mention: Guitar Hero III, Fire Emblem: Radiant Dawn, Madden 08, Mario Kart Wii.