9. Charlize Theron - Monster
As much as we can joke about the poor little beautiful girl having to pretend to be ugly for a film she's getting paid for, it really does take a lot of self-confidence to be willing to de-hotify yourself for a role. An actress's face is her living, after all, so it's not hard to imagine one being uneasy with the idea of straying too far away from her money-making visage. In Monster, Charlize Theron committed herself to playing serial killer Aileen Wuornos in an honest manner, which in this case meant changing the way she looked to fit the character. Theron gained 30 pounds for the role, wore subtle but extensive makeup, had prosthetic teeth put in, and even had gelatin applied to her eyelids so that they would droop, giving her a perpetually tired look.