Karan Pryor is an incredably expirienced trainer, and one of the 'greats' in the non-contact sports world. I have heard this book recommended a LOT. I have not read it myself however. As you said, at 25-40 bucks a book, I haven't read a lot of books I would like to.
A fun beginner book I read a while ago was "So your dog isn't Lassie". It is not for stupid dogs, but non-herding breeds. Addresses stubbornness, lack of drive, overdrive combined with stubborness, shutting down and all sorts of issues that most BC folks don't have to deal with. It is written in a humorous and sympathetic way, and the authors own dogs include English Bull Dogs and a Newfoundland-so they have worked with some hard dogs. As I said, it is a very beginner level, but I enjoy reading those, as it makes me remember to practice the foundation work.
Pam Dennison is another good author, although sometimes can get a little too PC. But her book Bringing Light to Shadow was amazing, and I highly recommend it to anyone dealing with or thinking about a fear aggressive dog. Just remember to have tissues with you towards the end!