Britney vs. Xtina: Fashion Face-Off!

Both Mouseketeers, pop stars, and now reality show judges -- but who's best dressed through the years?

The ladies wore matching wedding gowns when they joined Madonna onstage at the 2003 MTV Video Music Awards to perform "Like A Virgin." 9 more Britney vs. Christina fashion face-offs under the cut!

At the inaugural Teen Choice Awards in 1999, both pop tarts were reflective. Spears faced the cameras in pailette-covered pants, while Aguilera accessorized her shiny leopard print mini-skirt with a gold coin belt.

At the 10th Annual Billboard Music Awards in 1999, Spears looked ready for the prom in a lavender gown and white pashmina, while Aguilera looked ready to party in a sheer skirt and midriff-baring T-shirt.

Both ladies tried on more grown-up looks for the 2000 Grammy Awards. Spears' sexy halter gown was more polished, but Aguilera took home the trophy for singing talent.

Then 18 year-old Spears was the talk of the night when she ripped off her tear-away tuxedo to reveal a nude bodysuit at the 2000 MTV Video Music Awards. Aguilera's red leather two-piece was also hot, but did you see Britney's nude suit?!

Perhaps "Who was worst dressed?" is the better question here. At the 2000 Billboard Music Awards, Spears was big pimpin' in her ankle-length trench and feathered fedora, while Aguilera paired a boring white dress with stripper boots and skunky hair highlights.

The ladies used the spider web style to different effect at the 2008 MTV Video Music Awards. Spears' one-shoulder silver number was short and sexy, Aguilera's body-conscious gown was full-on glamourous.

The ladies both got the little black dress look right in 2009, with Spears showing off her trim figure at the Teen Choice Awards and Aguilera striking a chic pose at Variety's 1st Annual Power of Women luncheon.

In 2010, Spears struggled to recapture red carpet glory at the Grammy Awards as Aguilera hit her style stride at the Golden Globes.

At KIIS FM's Wango Tango 2011 concert, Britney ruined the look of her strapless frock with a pair of clunky boots. Aguilera's footwear choice for a press conference for The Voice looked downright dangerous.

This summer, Spears seemed comfortable in a sparkly beige dress while on tour withThe X-Factor, but Aguilera struck a sour note in a layered ensemble at a press event for The Voice.

What do you think, ONTD? Which pop diva's fashion sense do you prefer?