With me, it isn't just one book, it's the whole damn series. The Cirque Du Freak series are the greatest books I've ever read. They're about a boy named Darren Shan (also the author of the book) who is turned into a vampire, and becomes assistant to the vampire who transformed him. The whole series follows him through the troubles and triumphs that he deals with. The books are very exciting and interesting. It's very hard to put them down. I suggest that if you're into mythical creatures and such, that you should read these books.