You can probably list off at least a dozen bands who top Linkin Park for popularity--particularly in 2012--but as the saying goes, numbers don't lie. The Californian nu metalists have become the first band to amass over one billion views on their official YouTube channel (LinkinParkTV in their case).
The feat has already been achieved by three solo acts previously (not to deflate their victory in any way). Lady Gaga did the numbers in 2010, before being surpassed by Rihanna a year later. Justin Bieber (surprise, surprise) eventually topped them both, and currently stands as the most-viewed artist on YouTube with a cool 2.8 billion hits (and counting).