I've never been one for serious racing games. I guess its mainly because its hard to enjoy them using a keyboard on a PC, and the console systems I own are all Nintendo which means I don't really have a chance to play them there either.
Then for some reason I had the desire to try and play some more racing games. Starting with Trackmania Nations Forever, I soon desired to try something a little more realistic. Soon after purchasing my X360 wireless controller for windows (since I had some experience using it in the past playing at a mate's place and knew it was a solid decent controller) I decided to download the demo of DiRT to try it out the controller in a more realistic racing environment. The results lead to me purchasing the retail game as it was a fantastic experience.
DiRT is an off-road racing game by Codemasters. It basically features almost all forms of popular off-road racing involving 4 wheels, and does a damn good job at representing them. All this is rendered in high-resolution glory with plenty of sharp models and textures, high quality lighting and shadow effects along with a very complicated damage system that is on par with the Burnout series.
Couple this with the very solid X360 controller and you get a fun racing experience (taking into account how much money and space is saved over using a wheel + pedals).
Check out a short video I made recording a fun (and close) race I had only moments ago. It shows off the visuals pretty well, as well as gameplay itself (from a 3rd-person TV-esque perspective from the replay mode). You can find the video here: http://www.youtube.com/watch?v=oD9JsrfG0Bk