I would suggest Wind Waker, Metroid Prime, SSBM, and possibly animal crossing (I've never played it)
Like I just said, I've never played Animal crossing, but i think its something like The Sims.
Gamecube is the best system out there. The main reason that everybody wants PS2 is for GTA3 and Vice City, but now that they are coming to Gamecube there's no need to worry about that. And X-box just plain sucks. The graphics are good, but there's really only 1 good game.
There are a couple Final Fantasy game coming out for gamecube, but I don't know when.