Go buy GTR2 for PC...its like $9.95 at Bestbuy since its a year or two old..heck for $15.00 you can get GT Legends and GTR2 Bundled....the physics are much more realistic than most of the arcade style racers out there....it truly is a "simulator"
I will say that the new Forza graphics are much nicer looking than the two titles I've listed, but the driving doesn't compare (especially with a gamepad).
The Multiplayer features are great.... If you've already got em...lets race sometime.
Info can be found here ->
http://www.gamespot.com/pc/driving/gtr2/index.html
Helmethead