4. Demi Moore and Emilio Estevez
Demi and Emilio had a hit movie together: St. Elmo’s Fire. While they didn’t play a couple in the movie, there were sparks in real life. Emilio directed and starred in the cult classic Wisdom and had Demi play his love interest. Shortly before the wedding, they decided they were too volatile for each other and called it off. They’ve been friends ever since, though.