1. Joan Crawford vs. Bette Davis

The rivalry between Joan Crawford and Bette Davis is nothing short of legendary. Their bitter feud, which started in 1935 over a man, escalated during the filming of Whatever Happened to Baby Jane? in 1962.
Bette was nominated for an Academy Award for her role, and Joan reportedly went to great lengths to sabotage her co-star’s chances, even going as far as planning to accept the Oscar on behalf of another actress. The two never reconciled before their deaths, cementing their place in Hollywood history as one of the most iconic feuds of all time.