1. Super Mario Galaxy
2. Mario Kart Wii
3. Legend of Zelda: Twilight Princess
4. Super Mario Galaxy 2
5. Wii Sports Resort
6. New Super Mario Bros. Wii
7. Grand Slam Tennis
8. Super Smash Bros. Brawl
9. Wii Sports
10. Metroid Prime Trilogy
11. The Sims 2: Castaway
12. Monster Hunter Tri
13. Red Steel 2
14. Punch-Out!!
15. Okami
16. Guitar Hero III
17. Boom Blox Bash Party
18. Wii Play
19. House of the Dead Overkill
20. Mario Strikers Charged
Edited: Because I forgot about Okami before reading the list.
Other games I've wanted try but haven't got a chance yet are Silent Hill Shattered Memories, Dead Space Extraction, RE: DC, Endless Ocean 2, and Sin and Punishment 2 (which isn't out here quite yet)
Of the games I've played but didn't make my list I thought De Blob, Wario Shake It, Super Paper Mario were all disapointing. I've tried to get into FPS with Medal of Honor Heroes 2 and COD: WAW but it is just not my genre.