You know funny this topic should come up. I just did some counting courtesy of Wikipedia and out of 318 Wii games only 15 are party/minigames. This is all announced and released games. These games include:
Barnyard: Party Animals
Big Brain Academy: Wii Degree
Bomberman Land: Wii
Carnival Games
Cooking Mama
Cooking Mama 2
EA Playground
Mario & Sonic
My Word Coach
Rayman Raving Rabbids
Rayman Raving Rabbids 2
Wii Play
Wii Fit
WarioWare: Smooth Moves
Asterix at the Olympic Games
For those keeping track that's 4.7%. Now you want to tell me how Wii deserves it's mini-game machine reputation if the 360 doesn't deserve it's shooter machine reputation?