Everything I've ever read by Jim Butcher has been a LOT of fun. Not a perfect writer, but he started out in the "not bad" category and has been steadily, visibly improving. I don't have ratings up for the other novels of the Dresden Files, but that's only because I can't remember at this point how well I liked each individual book. The series as an ongoing single entity has been a phenomenally good ride, and Dresden is an irresistible character.