Animal Farm by George Orwell ($9) is a book so controversial, they didn't even want to publish it. Orwell's allegorical tale is meant to critique the Stalin era of the Soviet Union, but publishers were wary about releasing the book in 1945 out of fear of upsetting the alliance between the United States, Britain, and the Soviet Union. The book uses farm animals rebelling against their farmer in an attempt to create a society in which all animals are equal to show the dangers of trusting leaders who only have their best interest in mind. If you like communism taught through piggies, this is for you.