5. Maggie Gyllenhaal - The Dark Knight
Given the effort Christopher Nolan went to in re-casting Rachel Dawes, it's surprising that he brought her back only to kill her off. After all, she's the lynch-pin of Bruce's normality, and without her, he really has trouble staying afloat (as evidenced by his turmoil in The Dark Knight Rises). Still, Nolan played the scene in which she is blown up by The Joker extremely well, toying with audience expectation that love interests in blockbuster movies have to have verbose, drawn-out deaths. Instead, Rachel begins to say the typical sentiment spiel, only getting out the word "Some...", before the explosion rocks the building and blows her to smithereens. Though by the nature of her predicament it was possible she was going to die, the fact that Harvey Dent was at the other location - not to mention his bomb detonation and ruining his face made total sense - was a clever way to distract us from anticipating Rachel's fate.