No. 2: Britney Spears, ‘Till the World Ends’

Britney Spears makes the apocalypse look good in her sweaty, seductive video for her chart-topping, infectious club jam 'Till the World Ends.' Leave it to Ms. Spears to go out in style with her crew of hot backup dancers. Is there really a better way to spend Dec. 21, 2012 than at an underground dance party with Britney Spears? Everyone's welcome -- all you have to do to partake in this sexy good time is make it down a secret manhole before a meteor hits earth and completely destroys it. Pretty simple, right?