The Godfather (Francis Coppola, 1972)
At the end of the film, when Al Pacino [after struggling with his conscience] becomes the Godfather and he closes the door on his wife, Diane Keaton.
The Long Good Friday (John Mackenzie, 1981)
When Bob Hoskins is kidnapped outside the Savoy Hotel and driven away at the end [by the Irish gangsters he crossed] and he realises he's going to die.
E.T. The Extra-Terrestrial (Steven Spielberg,1982)
When no amount of technology can save E.T. and he is resurrected by his friend Thomas's love in the plastic tent.
Heat (Michael Mann, 1995)
When Robert De Niro is driving out of town to join his girlfriend [having pulled off the bank robbery], and is about to get away. You just know he won't be able to leave it at that and he's going to go back and get killed.
William Shakespeare's Romeo + Juliet (Baz Luhrmann, 1996)
At the Capulet's masked ball, when Leonardo Di Caprio and Claire Danes see each other for the first time and stare at each other through the fish tank.