Britney Spears's OMG Moments

Oh baby, ba-bay! With her signature girlish growl, Britney Spears bursts onto the music scene with the release of her first single, "…Baby One More Time." The song's music video, which shows the 16-year-old sporting a schoolgirl uniform that bares her midriff, stirs controversy. But Spears downplays her sex appeal, saying, "The outfits looked kind of dorky, so I was like, 'Let's tie up our shirts and be cute.'" The following March, she announces her first national tour.

Sporting a push-up bra and panties, the scantily clad 17-year-old lands on the cover of Rolling Stone's April 15, 1999 issue. But inside, she shares stories of her religious upbringing and her dislike of "party movies" and drinking in excess, saying, "You want to be a good example for kids out there and not do something stupid."

Jaws dropped at the 2000 MTV Video Music Awards when Spears takes her romance with 'N Sync member and fellow Mousketeer alum Justin Timberlake public. Later in the show, jaws hit the floor when she rips off her clothing to reveal a sparkly, flesh-colored ensemble for a medley of "Oops! … I Did It Again" and "Satisfaction."

For her return to the VMA stage a year later, the singer drapes a 7-foot albino python across her shoulders as she shimmies to "I'm a Slave 4 U." She later tells Entertainment Weekly the reptile was so "slimy" and "sticky," she broke into hives the first time she touched it.

Spears causes pandemonium when she shows up on the arm of actor Colin Farrell to the January 2003 premiere of his film, The Recruit. Though she slips out of the screening, the pair later reunite at the Chateau Marmont where they openly kiss. But Farrell dismisses relationship talk, telling Entertainment Tonight, "Seriously, we just met a week ago. [We're] having a laugh."

The singer shares a steamy smooch with original pop diva Madonna during the opening performance of the 2003 MTV VMAs. While Christina Aguilera also locks lips with the Material Girl, the cameras pan to the audience for ex-boyfriend Timberlake's reaction. "I didn't know it was going to be that long and everything," Spears says weeks after the kiss.

During a weekend in Las Vegas, Spears shockingly weds childhood friend Jason Alexander on January 3, 2004, wearing jeans, a belly-baring top and a baseball cap. But just 55 hours later, the couple annuls their marriage. "I was in Vegas, and it took over me, and, you know, things got out of hand," she later says on Total Request Live.

In March 2004, Spears kicks off the Onyx Hotel tour, during which the increasingly racy singer appears in the buff (save for a sequined body stocking) while writhing in a see-through bathtub and singing about masturbation. But only three months in, a knee injury forces her to cancel the tour's remaining 37 dates, which follows mediocre reviews and poor ticket sales.

Concern over the singer's bizarre behavior, which includes a quickie engagement with backup dancer Kevin Federline, reaches a fever pitch when she is repeatedly photographed walking around barefoot, including at an L.A. gas station bathroom in August. "Sometimes it just feels good to go barefoot in this heat and give her feet a rest," mom Lynne fights back in a post on her daughter's Web site.

A month before their planned nuptials, Spears and Federline say in front of just 27 friends and family on September 18 at what is billed as an engagement party. Calling the affair "my fairy tale dream," the bride walks down the aisle in a $26,000 Monique Lhuillier gown.

On May 17, 2005, UPN premieres Britney and Kevin: Chaotic, a six-episode series that chronicles the couple's early courtship. Though it features never-before-seen home video footage (during which Spears appears disoriented), the show fails to make an impression in the ratings and leadsviewers to question the duo's antics.

Two months before welcoming son Sean Preston, the parents-to-be attend the L.A. premiere of Charlie and the Chocolate Factory on July 10, 2005, with Spears playing homage to the film in a blue tank top that features an, ahem, downward pointing arrow and the quote "I've got the golden ticket."

Spears's parenting skills are called into question in February 2006, when she is snapped driving her 5-month-old son around seated on her lap. "I love my baby more than anything," she tells PEOPLE, "and as unfortunate an experience as this has been for me and my family, if it brings more attention to child safety then I fully support that."

Walking out unannounced on the Late Show with David Letterman, the singer reveals she is pregnant with her second child on May 9, 2006. "Don't worry, Dave, it's not yours," she jokes.

Though the star tells Harper's Bazaar that with pregnancy "you don't feel the most beautiful all the time," she strips down two months before giving birth to son Jayden James for the magazine's August cover. "It made me want to cry a little bit, doing these photos," she says. "I started feeling like myself again."

Only weeks after filing for divorce from Federline, Spears hits the party scene over Thanksgiving weekend in L.A., and accidentally exposes herself while stepping out of a vehicle with no underwear on.

Continuing her week of hard-partying, the single lady links up with frequent companion Paris Hilton and Lindsay Lohan for a night of clubbing in L.A. on November 26, 2006. "Paris was acting like Britney's boyfriend," says a source, "and Britney happily accepted Paris's friendly gestures."

Hot on the heels of her less than 24-hour stay in rehab, the troubled singer stops by a hair salon in Tarzana, Calif., on February 16, 2007, and shaves her hair off. A week later, she attacks a parked car with an umbrella outside of ex Federline's home when he refuses to let her in to see their kids.

As a heated custody battle rages on, Spears releases her fifth album, Blackout, and performs its lead single, "Gimme More," at the 2007 MTV VMA Awards on September 9. But her lackluster showing proves a disappointment, with the New York Times writing, "She was awful." The singer's performance inspires an episode of South Park and memorably made Chris Crocker, with his "Leave Britney alone!" rant, an Internet superstar.

The singer continues to spiral out of control that December, when she assumes a British accent, begins stepping out in a hot pink wig and hooks up with paparazzo Adnan Ghalib. "I think she's a great person," he tells ABC's 20/20. "It's unfortunate that she's the way she is, because of the people she surrounds herself with."

After locking herself in a room with son Jayden on January 3, 2008, Spears is removed from her L.A. home on a gurney following a four-hour standoff, and is hospitalized for mental evaluation. Though she is released shortly after, the incident leads to a longer stay at a UCLA psych ward in February.

With her family now in control of her affairs, Spears begins rebuilding her career in March, with a guest starring role as a receptionist in love with Josh Radnor's character on the CBS sitcom How I Met Your Mother. "She was hilarious in the table-read," says costar Jason Segel. "I got to see her do the run-through as well, and she was great." The success of her appearance leads to another cameo in May.

"I'm in shock," the "Piece of Me" singer says from the podium after winning video of the year at the MTV VMA Awards on September 7, which saw her take home her first-ever Moonman. Earlier in the night, she also collects trophies for best female video and best pop video.

Taking her act on the road again, the Femme Fatale tour kicks off in Sacramento, Calif., on June 16, 2011, with Rolling Stone declaring, "The night belonged to Britney." In October, Joe Jonas comes aboard as Spears's opening act, and receives a lap dance from the star. "It's a dream come true," he says.

After two years together, Trawick proposes to Spears on his 40th birthday during a December 2011 couple's retreat to Las Vegas. "Last night Jason surprised me with the one gift I've been waiting for. Can't wait to show you," the singer wrote on her Facebook page prior to revealing the news. Though Spears hoped the third time would be the charm, she and Trawick announced their split Jan. 11, 2013, the same day she left her post as a judge on The X Factor.