What is a realistic driving game

There's a few realistic driving games all of which have different gaming experiences. Here's just a few of my personal choices:

XBOX 360:
- Forza Motorsports 3

PS3:
- Gran Turismo 5

I don't have much experience for PC gaming, especially racing games. Sorry.

But in the end it's about personal choice, as there's other games like Need for Speed series which is a great game in my opinion.
Drag Racer 3 is a good game