In the first season, suffers from a "criminal of the week" episodic feel that doesn't do the show justice. Once it hits its stride, though - particularly in the second season, which IMO, is the pinnacle - its a show that has something for almost everyone. It's at times suspenseful, at others funny, but it always keeps at its center the strongest asset of the show - the relationship between Raylan and Boyd.
Watched the whole series. At little weak in the beginning and end, but pretty amazing for most of its run. It had some of the best supporting characters on TV and it was incredibly funny. This is a great formula for TV.