There is no difference between the ps2 and ps3 other than clear graphical and proccessing capabilities, even the controllers are pretty much the same, other than quickly adding a tilt feature, LAME.
The 360 clearly has the better games and has a damn good online gaming mode, but has a crappy controller .
It really depends what you want, if you want to be amazed by graphics then get a ps3,
if you like gameplay buy a wii, if you enjoy playing games and go online alot, buy the 360.