For people wondering about PS2 vs Xbox...I'd go for Xbox if you can help it. Xbox looks better, has faster loading, has a better controller IMO (although the button layout is a bit better on the PS2 in this case), and the PS2 version has a bug where when you double-jump, your shadow disappears! This makes lining up jumps harder, although I beat it on PS2 without much trouble, so it's not that big of a problem, just an annoyance.
Either way, you MUST play it, it's one of the greatest games ever! (and you don't HAVE to collect all the stuff in the game, I hate that too so I didn't bother with a lot of it)