Never played NFS1, but I had/still have (I think) NFS 2. Played it first when was 7-9. Totally awesome. Ford Indigo is one sick machine with great turning (atleast in the game).
Didnt have NFS 3(only played it once, and that was on a PS), High Stakes is OK normally, but once you start adding in cars that people make, that takes it to a whole new level.
Never really did play Porsche Unleashed, Hot Pursuit 2 I borrowed from a friend for a while; it wasn't bad, was average, but nothing amazing IMHO.
Underground 1 back in the day was fun (yes it was a ricer type game, but I found it fun. Zipping around in the Civic like a complete idiot while outrunning a fully-tuned Nissan Skyline

). I can drift multiple laps for the drift track where its basically two S-shapes connected together by the sides with the Honda S2000

. Too bad its a damn pain to drive that car in the game. Acura Integra isnt too shabby too in this game.
Underground 2 got a little strenuous and repetitive in the middle part of the career mode, and the ad placement was pretty annoying.
Most Wanted was nice, racing was intense but the damn rubberband AI is a pest at times(though without it, the races probably wouldn't nearly be close). The Lamborghini Gallardo (no not the Murcielago, but the Gallardo) is an absolute beast in the game; great accel, speed, and handling all in one. The Porsche Carrera GT was nice too but the damn high pitch squeal of its engine got annoying every so often. Boss races were fun.
Carbon I borrowed from a friend, finished it way too fast, was not exactly the best, just felt like it was lacking.
Reading some of the previews for Pro-Street, the game seems pretty decentI'm gonna wait before I actually get it to see how far behind the PS2 version of it is compared to the next-gen ones and also how good game is.