I got to admit it, NFS Underground 2 was, and after all this time, still is my favorite NFS game. The level of detail to which you can customize your cars are awesome. You can adjust a wide range of things from gear ratio to suspension, to even tire grip. It has some of my favorite race tracks, fantastic drift tracks, you can customize your cars differently for all different kinds of races etc.
It may lack police chases yes, but overall I'd rather play this then any other game in the series, including the XBOX360 or PS3 games. Why'd they stop on the Underground series?