If you have a Ps1 get Test Drive 5. It was the best back in it's day. Otherwise Forza or GranTurismo. Grid Autosport if you like to be part of the contracting and all, and F1 for seriousness.
I read an article online and it said Gran Turismo is were I go to drive, Forza is were I go to race. Overall it summed up Forza as more Racing and Trackbased with a lot of the same kind of things going on. We're as GT, lacking in AI status, has a better driving feel as you do more and work around more cars. Definiatly just my speculation though.
So (insert meaning of life and REALLY important stuffs here) and that's what I'm all about!
Life is about the Journey!