Let's see....
First party:
- Wii Sports
- Wii Play
- Wii Fit
- Wii Music
- Super Mario Galaxy
- Mario Strikers Charged
- Mario Super Sluggers
- Wario Land Shake it
- Animal Crossing City Folk
- Super Smash Bros. Brawl
- Mario Kart Wii
Third Party:
- Dragonquest Swords
- Nights Journey of Dreams
- Sega Superstars Tennis
- Mario and Sonic at the Olympic Games
- Sonic and the Secret Rings
- Sonic Unleashed
- Rayman Raving Rabbids 2
- Samba de Amigo
- Harvey Birdman Attorney at Law
- No More Heroes
- Cooking Mama Wii
- Zack and Wiki
Number of First Party titles: 10
Number of Third Party titles: 12
Yeah, third party titles dominate my gaming library (and I'm not even counting my nephew's library)