Psych was stupidly fun and most of the time interesting.
I used to watch all the Midsummer Murders but I'm not a huge fan of the newer Barnaby, it's not that the new actor is that bad but I don't think he's had the best sidekicks.
Not sure if it's more a cop show or a murder mystery but there is a NooZuland show called The Brokenwood Mysteries which I quite like too.