1. Obscure (257)
2. Odin Sphere (141)
3. Okage: Shadow King (97)
4. Okami (65)
5. One Piece Grand Battle (610)
6. One Piece Grand Battle! Rush (104)
7. One Piece: Grand Battle 3 (201)
8. One Piece: Grand Battle! Rush (81)
9. One Piece: Pirates Carnival (106)
10. Oni (495)
11. Onimusha 2 (214)
12. Onimusha 3: Demon Siege (199)
13. Onimusha Blade Warriors (113)
14. Onimusha: Dawn of Dreams (86)
15. Onimusha: Warlords (113)
16. Operation WinBack (277)
17. Orochi Warriors (309)
18. Orphen (80)
19. Orphen: Scion Of Sorcery (87)
20. Otostaz (49)
21. Outlaw Golf 2 (114)
22. Outlaw Tennis (189)
23. OutRun 2006: Coast 2 Coast (357)