I'm a fan of the Cleveland Browns, a team that has yet to put together consecutive non-losing seasons during my lifetime.
Also, I hate the Bills, but only because the local TV is a Bills market. That means that this weekend when the Browns and Steelers (two teams that make up about 80% of the local football fans) play each other it won't be on TV here because the Bills are playing an away game and that means they have to show that because of contracts.