9 / 10

Gangnam Style

"Gangnam Style," a music video featuring the infectious, meme-ready dance moves of a little-known South Korean rapper named Psy, became the most-watched video in YouTube history in 2012, racking up more than 815 million views and knocking Justin Bieber off the most-viewed throne. (Kevin Mazur/WireImage)

Year in Review 2012: Obsessions

Here are the top 10 obsessions that, as ranked by their search volume and percentage spike compared with 2011 on Yahoo!.