Yes, the Xbox and the Cube have better graphics, but they dont produce when it comes to game selection (compared to the PS2)
Both systems have great games and graphics, but I will take a well made PS2 game over a graphically rich Xbox, GCube game anyday.
Though I must admit, I am looking into buying a Game Cube this month. Cant say much about the X-Box though, it's not a very good system if you ask me. I heard about Halo, Played Halo, and thought the game sucked. What else does it have to offer... ?