16. Jennifer Connolly (Requiem for a Dream)
The whole cast could be on this list, but Jennifer Connolly deserves to be here over any of the others for her final scene alone. 'Requiem for a Dream' follows the tale of four people and their struggle with drug addictions (of varying forms) whose lives become shattered by their respective afflictions. Before this, Jennifer Connolly was mainly known for her role as child star in films like 'Labyrinth' and 'Once Upon a Time in America.' You only need to know that her incredibly intense crescendo (mixed in with the one of the most suicidal endings ever committed to film) in Requiem is one of great shock (and one that couldn't be further removed than what she had done before). If you are ever considering the use of hard drugs, then you need look know further than this performance to see the most extreme and volatile example of the paths it can lead you down.