5. Klinton Spilsbury - Legend of the Lone Ranger
Klinton Spilsbury was, by all accounts, a massive a*shole while filming the titular role in The Legend of the Lone Ranger. It is said that the pleasant Mormon man who auditioned for the part was not the same egocentric douche that turned up on the first day of shooting. Turns out the guy was a raging alcoholic. And this became extremely visible to everyone very fast. He was banned from two bars and got into at least one recorded fight. Everyone on the set hated him, but he had them over a barrel. He was their leading man. The crew were also becoming increasingly unhappy with his acting performance. Rather than anger the man, the powers that be decided it best not to rock the boat and that the most practical thing to do was to get through the rest of the shoot and figure it out afterwards. They promptly removed all of Spilsbury's dialogue and replaced it with new audio provided by actor James Keach. Now, I don't care how much of an alcohol-fueled monster someone is, it's always cruel to edit them so significantly out of a starring role without their awareness. The cruelty levels heighten when you consider that several co-performers (and James Keach himself) said that his performance really wasn't that bad. This would prove to be Spilsbury's first and last ever television or film credit. You may say that's justice - and I may be inclined to agree, but the humane side always says it's pretty dishonourable to screw someone over like that. Poor a*shole.