These are definitely a guilty pleasure. They infuriate me if I think about them too hard, and all of the errors make me want to become a copy editor, and yet I find myself staying up all night to finish them and picking them up compulsively one after another. I believe I read the 15 books in the series currently out in paperback in two or three weeks. I had the first novel, Guilty Pleasures, languishing on my bookshelf for years before I picked it up on a whim as part of my recent urban fantasy kick. They're incredibly addictive, if you don't think about them too much.
This is a series focused on Anita Blake, Vampire Hunter in the city of St. Louis. She raises zombies as a profession and consults with the police on supernatural investigations as a sideline. Over the course of the series, she faces increasingly powerful vampires, wereanimals, and various other forms of supernatural bad guys. I very much enjoyed the attempts to make a kickass female heroine with a lot of power. Sometimes it didn't work, but for the most part I appreciate the fact that she could handle herself in a fight and that the boys weren't the only ones with supernatural powers.
The best and worst aspect of this series is the sex. The novels progress from our female protagonist agonizing over who to date to lots of explicit sex scenes as it gets further into the series. Sometimes I found the scenes kind of fun, but sometimes I was overwhelmed by the amount and explicitness of the (pretty much always heterosexual) sex. I was also annoyed by the heroine's occasional stabs of conscience and the weird combination of prudery and licentiousness. The ambivalence about increasing kinkiness and the awkward attempts to reconcile old beliefs with new desires and behaviors feels very authentic as Anita struggles with her own sexuality, but it was at times annoying to read no matter how realistic it might feel.
Overall, this is a fun series with lots of good vampire, werewolf, and zombie power, complete with a kickass female lead who even sometimes manages to do some investigation. The Dresden Files are better in terms of developing the investigation and private eye aspects, but there's a lot more sex and relationships in the Anita Blake, Vampire Hunter series. Overall, I'd say it's good, dirty fun but not for the faint of heart.