Funny as I was gonna start a Gran Turismo 4 thread last week....
GT4 as Rick says is brilliant, it's got Le Mans circuits pre Mulsanne chicanes & post Mulsanne chicanes, Motegi, Fuji, Monaco & the 'ring (not the film!!) amongst others.
It's got a fair few prototypes from recentish years & plenty of other GT type motors.
But then if you get an Xbox you can chip it & put a big hard drive in it, so I've heard

Then you need never actually buy any games (if you've no conscience...)
It's also got a game called Project Gotham Racing which also has plenty of nice fast motors & also has the Nurburgring (although it seems a little different from the GT4 version, I've never been so I don't know which is closer to being "right") There's a new game due out in the next month or so called Forza Motorsport (or something) which is meant to be similar in style to GT4
That said most people own PS2's so it's easier to swap games & stuff with mates, but both have plenty of choice for games.
I'd go for both
