Last year, we ran a super-sized competition to determine the greatest pop song in modern history, from the ’80s to today. Now, we’re back — and this time, it’s all about honoring the best and boldest in music videos.

In what was a battle to the last second, Britney Spears' "Toxic" music video narrowly edged out Kelly Clarkson's "Since U Been Gone" by the slimmest of margins in our first-round matchup. In a 51% to 49% decision, you chose Brit's seductive, alluring lyrics over Kelly's super-charged, post-breakup anthem. The contrast between the two couldn't be more different: In "Toxic," Britney sings about the addicting nature of relationships, while Kelly celebrates the empowerment of breaking free from the chains of love. Bad girl Britney won out in this matchup and thus, it's only fitting that another sultry video challenges her in the next round.

In the late '90s, as Britney began dominating the charts, another young blonde singer entered the spotlight. Christina Aguilera struck music gold with her first hit, "Genie in a Bottle," and the industry pitted Christina and Britney against each other in a battle of the pop starlets. Both Britney and Christina appeared together on The Disney Channel's Mickey Mouse Club revival from 1993 to 1995, and so, a rivalry was born that the tabloids and newspapers couldn't resist writing about.

In our last round, we had Christina face off against another fellow ex-Mouseketeer, Justin Timberlake, in a battle between "Dirrty" and "Cry Me a River." "Cry Me a River" remains to this day one of Justin's most memorable hits, but "Dirrty" handily defeated his breakup ballad by a near four-to-one margin (78% vs 22%). Like "Toxic," "Dirrty" is often considered one of the singer's more risqué videos and thus, we can't wait to see how this matchup ends.

It's Britney vs. Christina all over again. Which video will move on to the next round?  The poll ends on December 2 at 5 PM ET.

And don't forget to vote in the other '00s semi-final round:

Lady Gaga, ‘Bad Romance’ vs. P!nk, Christina Aguilera, Mya & Lil’ Kim, ‘Lady Marmalade’

Christina's Most Outrageous Looks

Britney Spears Through The Years