We did it for PS2 and Xbox and we'll have a running list going for as long as we're alive, so here's the GameCube version. These threads should be especially handy to people who got their systems recently and want to start out with the "A List" of games to pick from.

So let's start the "A List". What would you add to it?

NOTE: * = exclusive to this system (for now)

1080 Avalanche *
Alien Hominid
Animal Crossing *
Backyard Baseball
Baten Kaitos *
Beach Spikers Volleyball *
Beyond Good and Evil
Billy Hatcher *
Bomberman Generations
Burnout (series)
Cubivore *
Donkey Kong Jungle Beat *
Donkey Konga *
Eternal Darkness *
F-Zero GX *
Game Boy Player *
Harvest Moon: A Wonderful Life *
Ikaruga
Legend of Zelda, The: Collector's Edition *
Legend of Zelda, The: Four Swords *
Legend of Zelda, The: Twilight Princess *
Legend of Zelda, The: Wind Waker *
Luigi's Mansion *
Mario Kart: Double Dash *
Mario Golf *
Mario Party (series) *
Mario Tennis *
Mega Man Anniversary Collection
Metal Gear Solid: Twin Snakes *
Metroid Prime (series) *
Pac-Man vs. *
Paper Mario 2: The Thousand Year Door *
Phantasy Star Online
Pikmin (series) *
Prince of Persia: Sands of Time
Resident Evil *
Resident Evil 4 *
Resident Evil Zero *
Skies of Arcadia
Smuggler's Run 2
Sonic Adventure (series) *
Sonic Heroes *
Sonic Mega Collection *
Soul Calibur II
Splinter Cell (series)
SSX Tricky
Star Wars Rogue Squadron II: Rogue Leader *
Star Wars Rogue Squadron III: Rebel Strike *
StarFox Adventures *
Super Mario Sunshine *
Super Monkey Ball (or MB2)
Super Smash Bros. Melee *
Tales of Symphonia *
Timesplitters 2
Tony Hawk Underground (aka THUG series)
Viewtiful Joe (series)
Wario World *
Wave Race: Blue Storm *