4. Beyoncé

In 2009, Beyoncé went global. It’s not as if she weren’t already one of he biggest stars on the planet, but over the past 12 months — spurred on by a mega-successful tour, a string of high-profile cameos, and the undying popularity of “Single Ladies (Put a Ring on It)” — she became an honest-to-goodness global force, a pop-culture phenomenon whose reach was perhaps bested only by the guy who made headlines for doing the “Single Ladies” dance, President Barack Obama.

So, like Obama, could a Nobel Peace Prize be in Beyoncé’s future? At this point, we’re willing to believe that she just might … especially when we’re talking about one of the most idolized — and influential — women in the world. In 2009, Beyoncé became so huge that truly anything is possible from here on out.

2009 Highlights: B opened the year by performing — twice — at Obama’s inauguration festivities, including turning in a genuinely amazing version of Etta James’ “At Last” for the first couple’s first dance. Of course, James didn’t think the whole thing was that amazing, ripping into Beyoncé during a performance the following month (though, to be fair, James would later say she was just joking when she made the digs).

Either way, Beyoncé just kept right on rolling, announcing plans for a massive U.S. tour, and watching as “Obsessed,” the down-and-dirty film she starred in alongside Ali Larter, took the top spot at the box office, hauling in some $28 million. She premiered the delightfully weird video for “Sweet Dreams” in early July, and racked up nine Video Music Award nominations — tied with Lady Gaga for the most of any artist — in August.

Beyoncé took her I Am … tour across the globe, playing 106 shows on four continents (she’ll add a fifth when she hits South America in February), grossing more than $53 million worldwide. And in September, at the VMAs, not only did she wow audiences with a larger than life rendition of “Single Ladies,” but she proved to be a genuinely nice person when, while accepting the moonman for Video of the Year, she invited Taylor Swift onstage to finish her acceptance speech (you know, after Kanye West ruined it).

She wrapped up the year by releasing the much-discussed clip for “Video Phone,” an eye-popping, seizure-inducing collaboration with Gaga, and by nabbing a staggering 10 Grammy noms, more than any other artist.

All in all, it was a pretty good run for the Queen B. And with a cameo on Alicia Keys’ Element of Freedom album and a near-certain Grammy performance on the horizon, 2010 is already shaping up rather nicely. Which means that someone should probably get the Nobel folks on the phone — no doubt they’ll want to put a ring on B too.

B also made news this year by admitting a weakness for “Super Mario Bros.” She inadvertently helped prank an Austrian museum. Though she might have recorded the same song as Kelly Clarkson, she was still fawned over by Adam Lambert. And amazingly, she did not break a hip after doing the “Single Ladies” routine an estimated 9,246 times in 2009.