Anyone who has their doubts about Metroid Prime should really pick it up or at least rent it. Great game, absolutely amazing how well and how much it feels like the orignal in terms of the elements that made it fun.
I can't compare it to any FPS on console or PC and this is coming from a person who doesn't like many console FPSs including Halo because they don't hold a candle to the PC FPSs I've been playing since Team Fortress (Quake, not HL).
There are some good console FPS, but Metroid Prime is unique and definately lives up to Super Metroid on the SNES. Any Metroid fan should give it a few hours chance and see if you can adjust to the controls and enjoy one of the best games the GC has to offer.
Oh, and I'm looking forward to Zelda, Metoid Prime 2, Pikmin 2, Mario Tennis, Paper Mario 2, Donkey Konga, Star Fox, and Resident Evil 4. I may end up adding all these to my collection of 15 and growing, I love my Xbox though I have a soft spot for the GameCube because it's a console that has soul IMO. Xbox and PS2 just seem more like your typical set-top-box you chuck on next to your home theater rather than the video game machines they are.