#10 Charlize Theron
Beautiful, graceful Charlize becomes the grotesque, the horrifying Aileen in the movie “Monster” (2003). She had to gain about 20 pounds, change her voice completely, and become a prostitute turned serial killer. For her stellar performance, Theron landed herself an Oscar for best actress in a leading role. In an interview, the actress mentioned that she loved the part, even though it was extremely challenging, too.