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17. ''Boys'' (2002)
A relatively minor entry in the catalogue — even if lesser pop stars would kill for that popping, Janet-esque groove, courtesy of the Neptunes.
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16. ''Born to Make You Happy'' (1999)
Maybe this disc needed one more ballad? This sweet but slight early entry from Brit's career doesn't really have ''Greatest'' written on it anywhere, though it's still a guilty pleasure.
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15. ''If U Seek Amy'' (2009)
Say it three times fast, and get your mouth washed out with soap. The song works up a minxy little schoolyard-chant buzz, but its obscenity tease is a little harder to forgive.
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14. ''Everytime'' (2004)
Though never known for her ballads, La Brit nailed a rare moment of vulnerability (''Every time I try to fly, I fall/without my wings I feel so small/ I guess I need you, baby'') on this mournful, piano-backed confession — rumored to be inspired by ex Justin Timberlake.
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13. ''3'' (2009)
Swedish pop maestro Max Martin guides the frantic lead single on this comp, and while it might not win her the PTA presidency, its salacious celebration of the pleasures of polyamory still rocketed it straight to no. 1 on Billboard's Hot 100.
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12. ''Womanizer'' (2008)
A stuttering, saucy dancefloor pounder from the girl who seemed like she could do some man-izing of her own, even if the lyrics are...lacking: The entire chorus wouldn't stretch the vocab of your average parrot.
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11. ''Stronger'' (2000)
Britney's early declaration of independence — ''my loneliness ain't killin' me no more'' — gave teen girls (and a little more secretly, the rest of us) a breakup anthem they could dance to.
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10. ''Me Against the Music'' (2003)
The meeting of two blond supernovas might not have yielded the pop-splosion all fans hoped for, but this duet with Madonna still worked up a sharp, saucy dancefloor groove.
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9. ''Radar'' (2009)
Brit sets her Doppler to stun; it's more like a sharp buzz, but it works.
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8. ''Gimme More'' (2007)
Not just the origin of the immortal ''It's Britney, bitch'' tagline — it's also a slinky, syncopated little hip-swiveler that not even a lackluster pole-dance of a video could dampen.
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7. ''Piece of Me'' (2007)
Missus Extra, extra, this just in: The star's first direct response to scrutiny and scandal was a fierce eff-you to those who thought she was done: a hiccuping electropop gem.
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6. ''Circus'' (2008)
When her life literally became a tabloid circus, Brit took it back with this synth-riddled big-top triumph: ''I'm a put-on-a-show type of girl,'' indeed.
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5. ''I'm a Slave 4 U'' (2001)
Not a girl — definitely more than halfway to a woman. The hip-snaking club banger from her third studio album revealed a Britney out of pigtails and into the night — a night where naughty, naughty things happen.
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4. ''(You Drive Me) Crazy'' (1999)
The third single from her debut — also co-opted for the Melissa Joan Hart/Adrian Grenier teen rom-com vehicle Drive Me Crazy — proved Spears was no bubblegum fluke with its soaring ''whoa-oh-oh''s and thumping, pep-rally-ready backbeat.
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3. ''Oops! ... I Did It Again'' (2000)
She's not that innocent? As Brit herself would say, yeah-yeah-yeah-yeah-yeah-yeah. But getting lost in the game Max Martin constructed was — oops! — more addictive than almost anything else on the pop market at the turn of the millennium.
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2. ''Baby One More Time'' (1999)
The then-17-year-old's unforgettable first single, in all its yearning, naughty-Lolita glory, burrows its way into the brain's pleasure center insidiously. And then never, ever leaves.
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1. ''Toxic'' (2003)
From the opening horror-movie synth shrieks to that cooed, breathy vocal hook, Brit's ode to boys-as-lethal-substances delivers mainlined pop sugar supreme — with a dash of arsenic.
Disagree with Leah's ranking? Defend your favorite track from Britney's new album in the comments section below, and share your own list ranking these 17 songs.