Adele's '21' is the best-selling album of 2011 in the U.S., moving 4.8 million units thus far. So, who better to grace the cover of the year-end/ year-in-music issue of Billboard than the singer? Billboard even dubbed 2011 the 'Year of Adele' on the front of the magazine!

Even though Adele was besieged by throat problems throughout the year, the album -- a product of a rather nasty heartbreak that the singer endured -- resonated with fans all over the world. Everyone was able to relate to what Adele was singing, but they were also alternately entertained and touched by the way she sang it. She was raw, vulnerable, honest, biting, emotional, scarred and beautiful all at once. If you think that's easy to do, you are sorely mistaken.

In the accompanying cover feature, members of Adele's team and her handlers speak about the talent they are blessed to work with. "Adele knows how good she is. You can't underestimate that. Artists that tend to work long term, most of them tend to have a clear-cut idea of who they are," said Rob Stringer, chairman/CEO of Columbia Records, her label in the U.S. "Adele can kind of do it all. She's never cocky... but she doesn't fear to tread, ever."

'21' is a global smash, having sold a whopping 13 million copies across the world in just 11 months. That figure gives the music industry some hope in an era of sagging record sales. Producer Rick Rubin, who recorded and produced much of the platter, weighed in on why this soulful Brit has such universal appeal, saying, "She said she wanted to make an organic album that was of one sound, not a patchwork quilt of different-sounding tracks pieced together."

With Adele healing from throat surgery, let's hope she makes it across the pond to the U.S. to play selections from '21' to her adoring audiences in 2012, continuing her trend of massive success.