12/01/2012 04:04 pm ET Updated Dec 02, 2012

Britney Spears' Style Evolution: From Pop Princess To Polished 'X Factor' Judge (PHOTOS)

We'll never forget the first time we heard Britney Spears on the radio. It was 1999 and we were in a friend's Volkswagon Beetle when she blasted onto the radio. We scoffed that this "pop star wouldn't last a minute." How wrong we were. The Louisiana native has been America's sweetheart for the past 13 years and we've watched her ascent to top-of-the-charts stardom (hello, that kiss with Madonna is the stuff that legends are made of) to her fall from grace. Now, we sit at the edge of our seats as the pop sensation embarks on a new phase of her life with a gig on "The X Factor" and an engagement to Jason Trawick.

The pop princess' style has always been "down-home." The self-professed country girl loves to be comfortable and we've seen her in everything from a head-to-toe denim tuxedo (with her boyfriend at the time, Justin Timberlake) to a boa-constrictor-as-necklace at the 2001 MTV VMAs, to pink wigs and denim cutoffs, and finally, in body-conscious dresses as a judge on "The X Factor."

To celebrate the pop princess' 31st birthday on December 2nd, we are taking a look back at some of her most memorable outfits. Vote on your favorites in the slideshow below.

Britney Spears' Style Evolution

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