In GT4, I started out with a JZA70, and I thought it handled really well right off the bat.... Maybe thats just me, though. Then I just beat Import Tuner Challenge (Tokyo Extreme Racer) with a JZA70, and it handled better than any other car I had in the garage (STI, RX-8, Fairlady Z32, FD, etc.). Umm, lets see... Forza 2, I've got a 7M swapped Mk3, and I've been destroying everyone with that. Also, NFS: Underground 1 & 2, Most Wanted, and Carbon, I've always bought the Mk4, and it always seems to do really well. I dunno, just my thoughts/experiences.
Haven't played Prostreet yet, though.... is it any good?