For Playstation 2, you cant be GT3, the range of cars, with the ability to make em pump some serious HP, for instance I have a Susuki thats making 1881Hp, if I set it up right I can make it fly on the high speed ring, and I mean that literally(as in all wheels off the ground)
Dont get much better.
For original Playstation, nothing beats Toca Touring Cars, for out and out door to door racing i reccommend it highly, it's one game where the opposing drivers actually drive hard, and u get race damage which slows your car so it is actually a pretty good sim.
For PC, nothing even comes close to GP4, every other F1 driving game is left for dead in what has to be the most realistic racing game ever. There is detailed setup and replays which u can save for performance analysis. Plus if gives you a real sense of speed, like your actually going 250 kmh
God I could go on about GP4 all night, until you play it you will have no idea how good it is. But as far as GP2 and GP3 go, it is like a different game all together.
Check it out at Microprose.com