#1 GT3.....got a PS2 just for this and it blew me away, graphics were mind boggling for the time and I'd just watch the replays over and over.
#2 Project Gotham Racing 2, Brilliant game What I would describe as Simcade. Kudos system was a LOT of fun.
#3 Forza 3 Spent a LOT of time on this collecting all the cars.
#4 Metropolis street racer (Yes I had a Dreamcast) daddy of PGR
#5 GT5 brings up the rear, such a disappointment for me and the last GT game I ever bought. Still spent quite a lot of time with the Premiums despite that, Spanish city track (forget the name) was really good.
Not bothering at all with Consoles now as PCs have caught up in the Graphics department and still have better physics and more realism (practise/quali etc).