Pure is a fantastic game, highly recommend it.
If you like rally cars, Colim Mcrae's Dirt is also excellent - I'm no sure if that's for PC though.
And if you want a free* (*I am pretty sure it's free....:O), yet good game, there's nothing better than Trackmania. Google it and download it - you'll love it! ^_^
Going with GRID (sequel to DIRT) definitely. Not too sim, but not too arcade.