Characters: Alma and Ennis del Mar
Movie: Brokeback Mountain (2005)

The relationship between Michelle Williams and Heath Ledger, both on- and off-screen, was tragic all around. In Brokeback Mountain, the film which brought them together, Williams played Alma, wife of Ledger's Ennis. The snag? Ledger's character was gay. That story was bound to not go well. In real life, Ledger and Williams dated for three years and had a daughter, Matilda, together. Their relationship reached an awful ending with Ledger's death in 2008.