The driving in Mafia II wasn't quite right but it was a lot better than GTAIV. In fact it was a much better game overall, although it was very linear in comparison. The graphics in Mafia II were excellent and if the city was as large as GTAIV and there was as much to do then that would be great in my book.
I haven't played much of SR3 but so far it seems pretty decent. I think the humour is a bit too much on the slapstic side but it's really enjoyable.
The driving in GTAIV was fun but it certainly wasn't realistic - all the cars drove like jelly the way they wobbled about. They couldn't get away with using the same vehicle physics for GTAV.