Adam Lambert

When season eight of "American Idol" premiered January 13, no one knew who Adam Lambert was or what he'd become. Sure, his first audition — he took on Queen's "Bohemian Rhapsody" — raised a few eyebrows, but in the early stages of the show, Lambert was outshined by the likes of Normund Gentle and that chick who wore a bikini.

That all changed with a vamping take on Michael Jackson's "Black or White," a decidedly demure version of the Smokey Robinson-penned "Tracks of My Tears" and, of course, his now-legendary cover of Tears for Fears' "Mad World." Suddenly, improbably, Lambert — the theater kid with the 100-octave voice and the penchant for dangly jewelry — became the "Idol" front-runner.

Of course, we all know how that turned out. Despite his defeat at the hands of Kris Allen in the season-eight finale, Lambert was unquestionably the biggest "Idol" star of the year, if not of all time. He graced magazine covers, pundits speculated about his sexuality — he was everywhere you looked. Post-"Idol," well, he just kept rising. In fact, Lambert was famous for all of 2009, which is why he comes in at #3 on our list.

2009 Highlights: Chances are, you're aware of his many on-air triumphs. But what about all the stuff that happened away from the cameras? For starters, he was the first "Idol" contestant in history to appear on the cover of a major magazine — in this case, Entertainment Weekly — while the show was still going on. He followed that up with a Rolling Stone cover story, in which he finally admitted he was gay.

He stole the show on a nightly basis during the American Idols Live! tour, battled with a label that was planning to release early songs he co-wrote and began touting his proper debut, on which he teamed with Lady Gaga producer RedOne (and, ultimately, Gaga herself).

In October, he premiered a delightfully over-the-top video for "Time for Miracles," the first single from the "2012" soundtrack. Then, in November, he began promoting his debut, For Your Entertainment, by closing out the American Music Awards with a shocking performance that featured nods to S&M, oral sex and some good old-fashioned guy-on-guy action. It was a display that rankled network censors (who cut out most of the graphic bits from the West Coast feed), created a firestorm of controversy and led to him being dropped from a scheduled appearance on ABC's "Good Morning America."

For his part, Lambert didn't let the criticisms weigh him down. He refused to apologize for the AMA performance and worked very hard to continue the promotion for Entertainment, which would debut at #3 with sales of more than 198,000 copies (by comparison, "Idol" winner Kris Allen's debut sold a paltry 80,000 in its first week). And when he was targeted by Eminem on the song "Elevator" (which used a little bit of wordplay to hide a very ugly anti-gay slur), he let it roll off his back, telling MTV News that he "didn't take it personally."

A lightning rod for controversy, a pop star bravely going where few have ventured (openly) before — Lambert was 2009. And we expect him to keep on pushing the envelope in 2010 too.