Well Forza 3 comes with an install disc, not used for anything really in the game that you can't get on the first disc, just extra goodness, so you only install that game and don't need to install the 2nd disc
That said, there hasn't been a game that has completely pushed any current gen console to it's limits yet, no, not even Crysis 2

_________________TwitterCharlie Brooker:
Macs are glorified Fisher-Price activity centres for adults; computers for scaredy cats too nervous to learn how proper computers work; computers for people who earnestly believe in feng shui.