Fall Out Boy and Panic! At the Disco are duking it out in a fan-voted competition for best throwback jam, so which pop-punkers will come out on top? FOB are competing with 'Sugar, We're Goin' Down,' while Panic! are in it with 'I Write Sins Not Tragedies.'

On 2005's 'Sugar, We're Goin' Down,' arguably the band's most popular song and their first hit to chart within the Top 10 on Billboard's Hot 100, Fall Out Boy waste no time, delivering a heavier, powerful intro that gives way to a rising, more climactic composition on the verses. It's more of lighter fare from FOB, but the music on 'Sugar, We're Goin' Down' ebbs and flows perfectly with the harmonies and lead vocals.

And while the lyrics, which have an extremely catchy tone, are about the ordinary aches and pains of young love, singer Patrick Stump takes the stick-to-your-brain track to a whole different level with his strong vocal performance, especially on the chorus: "We're going down, down in an earlier round / And Sugar, we're going down swingingI'll be your number one with a bullet / A loaded God complex, cock it and pull it."

Conversely, Panic! At the Disco had everyone exclaiming over their breakout hit, 'I Write Sins Not Tragedies,' which poised itself nicely at No. 7 on the Billboard Hot 100 back in 2006. The pop-punk track is laden with classical elements, giving the intro a somewhat eery vibe, although it's appropriate considering the lyrical content.

Delivered via Brandon Urie's begs-you-to-sing-along voice, 'I Write Sins...' spins a tale of the most f'ed-up relationship ever: "As I'm pacing the pews in a church corridor / And I can't help but to hear / No, I can't help but to hear an exchanging of words / 'What a beautiful wedding! What a beautiful wedding!' says a bridesmaid to a waiter / 'And yes, but what a shame, what a shame the poor groom's bride is a whore.'"

So, which pop-punk tune was and still remains, one of your all-time favorite throwback jams? Vote for either Fall Out Boy's 'Sugar, We're Goin' Down' or Panic! At the Disco's 'I Write Sins Not Tragedies' below. You can vote once per hour until Wednesday, May 15 at 11:59 PM EST, when the poll will close. A winner will be announced the following Thursday, May 16!

Watch the Fall Out Boy 'Sugar, We're Goin' Down' Video

Watch the Panic! At the Disco 'I Write Sins Not Tragedies' Video

Rules of Throwback Thursdays: On the third Thursday of every month, we will select two tunes for readers to vote on in a head-to-head competition for the greatest throwback jam. You can vote once per hour until the poll closes on the third Wednesday of each month at 11:59 PM EST. The cycle then continues, with a winner being announced the following Thursday, as well as a new duo of dueling songs for you to vote on.