I play NFS games on the PC with a Dual Shock adapter-playing them on the PS2 is just outright PAIN-insanely messy, low-res graphics and wobbly-as-hell framerates make driving a nightmare. Those things are allievated on the PC and the game plays really well there IMO-for a NFS game.
My main beef with the NFS games is that the AI is just plain terrible. Especially at competitive racing-it rubberbands to hell and makes any race past the newbie stages a matter of being ahead right at the end, since you can't build an effective lead through superior driving.
The series, as a whole, has been consistently solid the last few years. There isn't a real stinker in the whole lot outside of the PSP title, which I hear really stinks. Even NFSU 2 was a pretty decent game-not great, but not bad either.