PS2 has more and better games.
XBox has superior technology, so better long-term prospects. And, it does have some real gems.
I'm not sure how many games on either of those platforms are appropriate for 10-year old girls, though.
Gamecube is more of a 'kids' system - Nintendo generally does 'kid-friendly' games (you'll never see Nintendo do a 'Grand Theft Auto' ) Plus, it's cheaper.
However, if you are typing on a message board, you obviously have a PC. Why are you looking at a counsel?
PC games are better, more immersive, and the multiplayer components of them allow for much more interaction. (Yeah, I know many of the counsels are moving to internet multiplayer, but none have it implemented yet - and I just can't imagine a game like Everquest ever being ported to a counsel!)
Not to mention - if you pick carefully - PC games can be a healthy combination of educational and fun.
Xander F
(Unseen Apostate Directorate of North America - Ohio order)A fanatic is one who, upon losing sight of his goals, redoubles his efforts.
--George Santayana