"Gangnam Style," by Korean pop/rap star Psy, is the most watched YouTube video ever. In less than a year, it's racked up over 1.3 billion hits. Billion. The entertainer's pony-riding dance and sarcastic attitude have hit a universal chord.
(Read More: 'Hey! Sexy Lady!': 'Gangnam Style' Artist Hits the US.)
Well, sexy lady, Gangnam Style is so 2012.
Here comes the "Harlem Shake." The new dance craze hit YouTube less than two weeks ago and already has over six million hits.