Good cast chemistry, plust not all of them are the 'young and hip' sort of crowd which while not hugely unique is a good selling point.
-location -cast chemistry -THE BOSS -character interaction -types of crimes -reasons for transition from cast changes -good use of recurring guest stars Anyone with something else to add?
i know this, big bang theory and how i met your mother are the only shows i can watch over and over and not hate it