Below are the metacritic scores of the top 10 Gamecube and Wii third-party console exclusives. When adding up the score, youll notice that the Wii comes well ahead of the GC in terms of quality third party video game.
Ive omitted and added a number of games, including Resident Evil 4 for the Gamecube (which wasnt a third party GC exclusive in the previous generation, as it arrived on the PS2) and PGA Tour 10 Wii ( which was so fundamentally different from the other versions, that I consider it a Wii exclusive on the strength of its unique features).
Anyway, here are the games and their metacritic scores:
GC
Resident Evil 91
Super Monkey Ball 2 87
Super Monkey Ball 1 - 87
Tales of Symphonia 86
MGS: Twin Snakes 85
Resident Evil Zero 83
Final Fantasy: Crystal Chronicles 80
Pacman Vs. - 78
Battalion Wars - 76
Baten Kaitos Origins - 75
Avg Score: 82.8
Wii
World of Goo 94
Resident Evil 4: Wii 91
Tiger Woods PGA Tour 10 - 88
Zack & Wiki 87
Little Kings Story 87
LostWinds: Winter of Melodias 86
Boom Blox Bash Party 86
Boom Blox 85
No More Heroes 83
Dead Space Extraction 82
Avg Score: 86.9
That's pretty damn impressive considering the Wii is still in its infancy and the gaming press is biased against the system.
EDIT: Removed VJ from the GC list. I forgot it came out for the PS2. Added BW.
EDIT 2: Removed Ikaruga from the GC list. Added BK: 0