I haven't watched a police procedural in awhile, but this one is pretty good. Great characters (w/ some exceptions, but they definitely focus on the more interesting ones) and dialogue, not your usual cop-show storylines and a great soundtrack (I really want to find a listing of the songs used in this show.) Michael Imperioli (Christopher from the Sopranos) heads an excellent ensemble cast.
The first season, still in progress, is streaming on Hulu.