Britney Spears' Big 2011: From A Smash Album To A Ring On Her Finger

A decade into her career, the pop megastar reinvented herself this year as the ultimate Femme Fatale and made a big commitment to Jason Trawick.

Maybe Britney Spears' lucky number is 30. The singer turned 30 this year, marking the landmark birthday on December 2 with a fan-voted MTV News tournament that crowned the Best Britney Video of All Time. But her 30th year also proved to be an incredibly successful period in her career.

For the first time in a while, she seemed comfortable being the pop megastar that she is. More than a decade into her career, Spears re-emerged as a Femme Fatale, giving fans a fist-pumping album, embarking on a flashy tour and dropping more memorable music videos. Britney Spears fandom was reenergized as the singer came out of her shell, opening up about this phase in her career as well her personal life in several high-profile interviews. So it's probably not surprising that Spears will cap off the year at #4 on MTV News' Top Newsmakers of 2011 list, just behind Lil Wayne.

"When I was younger, I was busy, busy, and I was always singing and dancing all the time. I was just really creative," she recalled in the MTV special "I Am the Femme Fatale." "That's when my mom realized I'm a really creative person."

She let that creativity shine over the past 12 months. From "Hold It Against Me" to "Till the World Ends" to her Chris Marrs Piliero-directed "I Wanna Go" and "Criminal," Britney made headlines every time she dropped a music video. But no vid stirred up as much controversy as her "Criminal" clip, which featured real-life boyfriend (now fiancé) Jason Trawick — and his abs.

"At the end of the day, Jason killed it," Piliero told MTV News of Trawick's cameo. "That was one of those things I was really stoked [about], as much as I went into it like, 'Wow, he's not an actor. This is going to be interesting,' but I really do like a challenge, and I really do like the idea that I'm a director and my job is to direct and get the performance. For me, it was a fun challenge to be like, 'I'm gonna make sure that you are awesome,' and he was."

Between video shoots, Spears hit the road with the likes of Nicki Minaj, Joe Jonas, and DJ Pauly D. Spears fully embraced her sensuality on the Femme Fatale Tour, a spectacular show full of costume changes, elaborate stage setups and stunning mini-films.

And while much of the 2011 VMA buzz was about Beyoncé's baby bump and Jo Calderone, Spears stole the spotlight by walking away with a Moonman for Best Pop Video and the prized Video Vanguard Award. She also had tongues wagging after an onstage kiss from Jo (a.k.a. Lady Gaga), just before she was honored with an electrifying dance tribute that highlighted some of biggest career moments.

"It was really crazy. I had no idea what to expect," Spears told us backstage at the VMAs. "The kids were amazing and so entertaining, and it was a really fun night. It was really cool. I was like, 'Wow, that's really sweet!' "

As 2011 came to a close, Spears wrapped up her tour, and MTV News threw her a birthday bash in the form of the "30 Videos for 30 Years" tournament. The competition was heated but in the end, Spears' iconic "I'm a Slave 4 U" took home the prize. And just when it seemed things couldn't get any better, Britney confirmed she was engaged to Trawick after dating for two years. She showed off her Neil Lane ring during a celebratory weekend in Las Vegas.

MTV continues our Best of 2011 coverage by looking back at the biggest pop-culture stories of the year. As we count down the newsmakers that mattered to you most, also check out our Best Artists, Best Songs, Best MTV Live Performances and Best EDM Artists of 2011.