Monk, Season 2
It just gets better and better. The hit rate of excellent solutions is high and even when you know what happened the chase is pretty good. My bet is that it continues to focus on a split between pure "What is going on" episodes and classic Columbo style chase a known criminal episodes. The characterisation of Monk when he irritates his suspects like Columbo is excellent and I will keep watching partly just for that. It's funnier than much of what passes for comedy as well.