1. Christian Bale - Everything
Christian Bale should star in one of those after-school specials that tells young girls what
not to do. Before he closed out Nolan's Dark Knight trilogy, Bale had become infamous for pushing the boundaries of where an actor would go, with his weight constantly in limbo. He yo-yoed between the lows of the the crack addict Dicky Eklund in the Fighter and the prisoner of war Dieter Dengler in Rescue Dawn. But between the films, he buffed up in Reign of Fire and as the role of Batman. But most shockingly was Bale's performance in 2004's The Machinist, where he dropped over 60 pounds to weight a minuscule 120 pounds. Immediately after filming of the Machinist ended, he got huge again before re-introducing the world to Bruce Wayne.
Honorable mentions: Anne Hathaway in Les Mis, Renee Zellweger in that one awful movie. Anything I missed? Leave a comment or find how to get at me in my bio below.