Like the question about a favorite CD/album, I had a hard time narrowing this down. I love books and I love so many different authors. Depending on my mood, I enjoy pretty much any genre... though mysteries and memoirs are probably my overall favorite types.
When it came to choosing a favorite book, I narrowed it down to a favorite series. The "In Death" books are set in a futuristic version of New York City and are about a homicide detective solving crimes. I don't know what it is about these books specifically that has me so hooked, but I just enjoy them so much. I'm very invested in the lives of these characters. There are probably close to 40 books in the series at this point, and I've read every one. I get very excited when I hear that a new one is coming out - I even mark it on my calendar with a little reminder so that I can be one of the first to request it at the library.