One of Hollywood's most famous romances, Hepburn and Tracy met on the set of 1942's Woman of the Year and sparks flew. The only problem: A devout Catholic, Tracy would not divorce his estranged wife. The couple, however, carried on a 25-year-long and complicated relationship (Tracy reportedly had affairs and they broke up several times) and starred in eight more films together. He died shortly after wrapping their last film, 1967's Guess Who's Coming to Dinner, for which he earned a posthumous Oscar nomination and Hepburn her second Oscar. Hepburn didn't attend his funeral out of respect for Tracy's wife and never watched Guess Who's Coming to Dinner.