Benedict IX was already mentioned but I'd like to add that he was a pope 3 seperate times, and that he was forcibly removed at the end of at least one of these occasions. They bought the papacy off him at least one other time. He was actually excommunicated and in official catholic records he is painted as being plain evil.
I believe I remember he was accused of satanism as well, but that may well have been another pope.
I believe I remember he was accused of satanism as well, but that may well have been another pope.