It has to be "The God Delusion" by Richard Dawkins. To sell over a million copies of self-aggrandising yet depressing chatter is certainly an achievement, but I was disappointed that Dawkins spends so little time searching for truth and a lot of time talking about himself, which is not only boring but a travesty as the book masquerades as an academic work, when it really is little more than the exposure of Dawkin's own bigotry. Also, any of Donald Trump's books on personal success are a waste of time, for the same reasons.