Wow i don't even know if i can find 20 games i like, let alone rate them. here goes.
Okay they're not really in perfect order, but heres my top 20:
20. Goldeneye: Rogue Agent
19. Ratchet and Clank
18. No One Lives Forever (very under-rated)
17. Crazy Taxi
16. Halo
15. Elder Scrolls IV: Oblivion
14. Rainbow Six Vegas
13. Resistance Fall of Man
12. EA Sports NHL Series
11. Madden NFL Series
10. Star Wars Battlefront
9. Need For Speed: Hot Pursuit 2
8. Crash Bandicoot 2
7. Gran Turismo 4
6. Gran Turismo 2
5. James Bond: 007 Nightfire
4. SOCOM II: US Navy Seals
3. Crash Bandicoot 3: Warped
2. Call of Duty 4
1. Gran Turismo 3
Current Generation Games:
5. Uncharted: Drake's Fortune
4. Elder Scrolls IV: Oblivion
3. Resistance: Fall of Man
2. Rainbow Six: Vegas
1. Call of Duty 4: Modern Warfare