50. Sandra Bullock
Worst Performances: Speed 2: Cruise Control (1997), The Lake House (2006), All About Steve (2009)
That's right, we're calling out America's big-screen sweetheart. Let's ignore her ridiculous win at the 2010 Academy Awards for the hackneyed white savior flick The Blind Side here and stick with Bullock's biggest cinematic offenders: Speed 2: Cruise Control, The Lake House, and All About Steve. Granted, all three of those flicks would have sucked without her presence, but the A-lister's low-level performances managed to make already poor films that much more unbearable.