Is there a book that you wish you could "unread"? One that you disliked so thoroughly you wish you could just forget that you ever read it? (Suggested by C in DC)
I'm one of those people who rarely stops reading a book after starting it, so there are a few books that I wish I had never picked up. As for "unreading", I don't think I want to forget that I read those books; at least I should be able to remember not to read the same books (or similar ones) in future.
If I had to mention books that I would rather never have read, I'd name Lucky Jim by Kingsley Amis, Nineteen Seventy Four by David Peace, Catch-22 by Joseph Heller and The Road to Gandolfo/Omaha books by Robert Ludlum.
Do you ever continue reading a book despite knowing that you won't like it, thereby adding list of books to "unread"? Or do you stop reading the moment you know the book isn't the kind you like? I believe I'm in the minority that reads books anyway even when the know they don't like it.