Game Cube or Playstation 2

ps2 has backwards compatability so it can play your favorite old ps1 games. GC does have very nice graphics indeed.
Metroid Prime is a pretty cool game, but i still think super metroid for SNES was the best because it was a side scroller. Thats what i think of when i think 'metroid'. The first person is cool, but i would have much rather preferred an optional third person camera angle.
both consoles are good though, but personally i prefer ps2 because it has more games that appeal to my tastes, so just look at it from that perspective, which games you want.