Quite a few people here have. We have some ardent fans too (@Regula). It's one of the best ongoing series out there, IMO. Highly recommended! The first 2-3 books are bit rough around the edges, but still quite enjoyable, however starting from book 3-4 it picks up the steam and gets better and better with each book. Small Favor (Book #11) and Skin Game (Book #15) are two of my favorite books I've ever read. The first few have more self-contained plots, but as the series progresses, more of the bigger meta-plot is revealed. Summer Knight (#4) was where I got hooked and read the rest of the series without any breaks. If you want to listen to some of them, the audiobooks are fantastic. James Marsters brings DF to life. I know @Alucard didn't like the books as much. Maybe she could offer some contrasting views.