Okay, forget all these fanboys here. Save your money, get a job, and then buy yourself a year at college. It'll help you out a lot more in the long run.
Speaking seriously, I wouldn't listen to SAJN. He's a complete Nintendo fanboy in the worst way (coming from someone who's named after a NINTENDO CHARACTER) and he's got a 100% biased opinion.
The X-Box? It's good. It's got its ups, its downs. There are some awesome games out for it (Ninja Gaiden, Halo, Halo 2, Fable), there are some fairly decent ones, and there are some bad ones. Same with the GC.
Honestly, if you've got a PS2 (which I didn't feel like reading through the fanboy fodder so I have no idea) I wouldn't get it for RE4, as it will be coming out later this year. There are other solid games for it, but if that's your one reason for getting it...
Animal Crossing--addictive, fun, think Sim's without the upkeep and more interaction instead of the feeling of being god
F-Zero GX--solid racing game, quite fun, holy hell is it fast paced
Mario Kart:DD--I hated this title. At least in comparison to the other two Mario Kart titles. It's a decent game, but if you want an opinion on it...well don't ask me.
Pikmin--if you're into that kinda thing
Metroid Prime 1 and 2--Aparrently one of the best games out for the consoles. *shrug*
New Zelda Game--YES!
If you have a PS2 then I suggest a few games if you have some $$ left over (which you probably will).
Metal Gear Solid 3--do I need to explain?
GTA:SA--if you like GTA games, you'll LOVE this.
Burnout 3--better on the other consoles, but it's out for this one too...so hey. If you end up not getting another console, why not? Great game
Wild Arms 3--most underrated RPG ever