No Nintendo-published GC game is ever going to be rare, except maybe Geist.
From the NPD thread (all are life to date totals)
Super Smash Bros. Melee: 2,909,585
Super Mario Sunshine: 2,100,334
The Wind Waker: 1,956,861
Mario Kart: Double Dash!!: 1,903,955
Luigi's Mansion: 1,718,470
Metroid Prime: 1,308,052
Animal Crossing: 1,062,012
Mario Party 4: 977,513
Pokemon Colosseum: 934,985
Mario Party 5: 831,269
Star Fox Adventures: 821,771
Mario Party 6: 706,708
Pikmin: 678,379
Mario Golf: Toadstool Tour: 671,415
Paper Mario The Thousand-Year Door: 649,086
Kirby Air Ride: 550,968
Metroid Prime 2 Echoes: 535,784
Final Fantasy Crystal Chronicles: 463,586
Mario Power Tennis: 420,228
Donkey Konga: 357,280
Four Swords Adventures: 352,534
Wave Race: 336,172
F-Zero GX: 307,308
Eternal Darkness: 288,654
Pikmin 2: 281,055
Wario World: 263,264
Star Fox Assault: 247,808
Donkey Kong Jungle Beat: 207,615
Pokemon Channel: 182,246
Custom Robo: 175,304
Preview Disk: 172,709
NBA Courtside 2002: 160,796
1080 Avalanche: 154,489
Wario Ware Inc: 136,825
Magical Mirror: 125,302
Donkey Konga 2: 69,356
Geist: 10,393