I don't know if I can manage to make a top 20 but I'll try.
1. Metroid Prime Trilogy
2. Super Mario Galaxy
3. Metroid Prime 3
4. Legend of Zelda: Twilight Princess
5. Muramasa
6. Sakura Wars
7. Monster Hunter Tri
8. Trauma Center: Second Opinion
9. Trauma Center: New Blood
10. Super Smash Bros Brawl
11. Disaster: Day of Crisis
12. No More Heroes
13. De Blob
14. Zack & Wiki
15. Wii Sports
16. Mario Kart Wii
17. Animal Crossing
18. MadWorld
19. Excite Truck
20. Tales of Symphonia: Dawn of the New World