The Tony Clifton (Andy Kaufman) Taxi incident (lost recording by Tony Danza; 1978)
In 1978, performance artist and comedian Andy Kaufman reluctantly signed on to the sitcom Taxi to play a variation of his "Foreign Man" character re-named "Latka Gravas". Among Kaufman's numerous stipulations was that his alter-ego character, "Tony Clifton", an obnoxious, abusive lounge singer, would be guaranteed a certain amount of guest appearances. So, what was meant to be Clifton's debut episode "A Full House For Christmas" was written, with Tony playing Nick DePalma, the gambler brother of Danny Devito's character, Louie. Kaufman, whose Latka character was absent from the episode, would make a "guest appearance."
Clifton was reportedly miserable to work with, doing things such as bringing prostitutes to work with him (and declaring that he had re-written the script to include them), angering everyone present, and generally being unable to act. The decision was then made to fire Clifton and replace him with another actor. On the day this was to take place, cast member Tony Danza brought his Super 8mm camera to the set to document it. Ed Weinberger, the producer, then told Clifton that he was fired, which sent him into a tirade leading to him, Weinberger, and cast member Judd Hirsch getting into a wrestling match on the floor, with Danza recording the entire thing. Clifton was then removed from the studio by Paramount security. Several days later, while Danza was screening the film for his co-stars, Andy (back as himself), walked into the room and watched the film as well. He remarked that Clifton was "an asshole".
Danza's footage of the incident hasn't ever been seen by the public and it's unknown if the footage still exists to this day. The only physical evidence of the event publicly available are a couple of still photos (taken by Kaufman's co-writer Bob Zmuda) of Andy being removed from the lot by security guards in-costume. The film was recreated in the 1999 Kaufman biopic Man on the Moon.