Need For Speed: Porsche Unleashed, for PC. In the poll I had to vote other although it's an NFS game because other NFSs (apart from the latest on PC which I haven't played) are stupid and boring arcade style driving games but Porsche Unleashed was different and had a more realistic approach.
Also Geoff Crammond's Grand Prix series on PC was good, though I haven't really played it in recent years anymore.
And ofc those games need to be played with a steering wheel and pedals (except Crammond's first GP could only utilize keyboard (and mouse too, but mouse sucked) because with keyboard they're not that interesting.