Dude.
Is this even a question?
Needless to say, PS2 was definitely the best. The Xbox lacked titles, and the GameCube was getting a little old then. Though the GameCube and Xbox's graphics were better, what's the point of having great graphics if you don't have any games?
It would be like so:
1. PS2
2. GameCube
3. XBox
I was tempted to put GameCube as #1 just because of NFL Street.
And hell, game cube had wireless controllers, which was something the PS2 lacked. I don't remember about the Xbox, since I never saw those around.