1980: An estimated 83 million viewers tune in to find out "who shot J.R." on the prime-time soap opera "Dallas." The character J.R. Ewing, played by Larry Hagman (pictured), had been shot in a season-ending murder attempt in the March 21, 1980, "A House Divided" episode. Viewers had to wait all summer to find out if J.R. would survive and who shot him in an episode titled "Who Done It?" It's revealed that Kristin Shepard, J.R.'s mistress, played by Mary Crosby, was the character that fired the gun. "Who Done It?" was, at the time, the highest rated television episode in U.S. history.