One book you wish had never been written.
To which nin provides the excellent answer
Portrait of the Artist As A Young Man
I nominate Catcher in The Rye. Readers: too liberal to actually burn a book, but wish to register your artistic disapproval in no uncertain terms? Vote here. A real book, though. Please don't be arch and suggest The Communist Manifesto, Mein Kampf, Protocols of the Elders of Zion, or even the Da Vinci Code.