I'm kind of late with this one...but the thing is, I just can't think of a book that makes me "happy" - or, at least, my definition thereof. There are many books that make me laugh until my belly aches, but I wouldn't call that "happiness". Reading Proust or Tolkien gives me a sense of contentment, but it's still too low-level for me to call "happiness". Inspirational books don't really work on me - I like Coelho's imagery and prose and de Mello's philosophy, but I don't feel like my eyes have been opened and am feeling happy to be alive or anything. So...I'm afraid I must give this one a pass.