Cold Case is one of the greatest procedural dramas I've seen. I loved the fact that every episode took place in a different time period. Each of the sets and the costumes were meticulously crafted for every episode. The visuals and the dialogue were appropriate for each era. Even though the main characters were not as prominent as other shows, we still got to see the personal lives of each main character. The dialogue was especially good, I particularly like that it was peppered with old school phrases and words. Perhaps these two elements were what many people didn't like about the show. The music was amazing and was right for every episode, one of my favorite aspects of the show. I thought all these elements were what made it unique and differentiate itself from insipid shows.
The cast fit in their role beautifully. Kathryn Morris as Lilly Rush (one of her best roles), John Finn as John Stillman (good diverse actor), Jeremy Ratchford as Nick Vera , Thom Barry as Will Jeffries (great back and forth banter between Ratchford & Barry), Danny Pino as Scotty Valens (he fits right in with L&O:SVU), and Tracie Thoms as Kat Miller (I liked her in Rent as well).
My favorite episodes are Shuffle, Ball Change (S4 E17) and The Road (S5 E15). I still think the show was cut too short. I hope there are more shows like this one, especially since there seems to be less and less police procedurals.