The essential Christina Aguilera
''Genie in a Bottle,'' Christina Aguilera (1999)
The shuffling midtempo track that introduced most of America to Aguilera also happens to be the strongest selection from her self-titled debut disc. Sure, it's a big tease: Those plinking keyboards are more nice than naughty; the cheeky lyrics (''Hormones racing at the speed of light, but that don't mean it's gotta be tonight'') are decidedly PG-13; and Aguilera only hints at the power in her vocal arsenal. But then again, there's nothing wrong with age-appropriate product from a singer who was still best known (at the time, anyway) for her work with Mickey Mouse.
''So Emotional,'' Christina Aguilera (1999)
Aguilera goes smooth on this track smooth jazz, that is. Unlike much of the material on her overwrought debut disc, ''So Emotional'' reins in the singer's sometimes histrionic instincts. What's more, as interpreted by the teen diva, what could've sounded like a rejected track from a Vanessa Williams or Toni Braxton recording session instead gets infused with enough sweetness that dare we say it it gives easy-listening a pretty good name.
''Lady Marmalade,'' Moulin Rouge Soundtrack (2001)
Yep, the lady is a diva! Listening to Aguilera's collaboration with Mya, Pink, and Lil' Kim, you can practically hear her straining against producer Missy Elliott's leash, dying to assert vocal superiority over her lesser counterparts. And indeed, by the time Xtina gets let loose on the final verse, her vicious howl-eration proves, without a doubt, who's top dog in the quartet. Girlfriend's so off the chain, one could imagine the song's seminal interpreter, Patti LaBelle, baring a tooth or two.
''Dirrty,'' Stripped (2002)
The lead single from Aguilera's second English-language disc was awesomely misunderstood perhaps in part because of a jarring, David LaChapelle-directed video that introduced the world to Xtina, the singer's stringy-haired, chaps-clad, hoochie-dancing, underground-pugilist alter ego. All that aside, though, three key elements Rockwilder's bone-crushing bassline, Aguilera's guttersnipe-in-heat delivery, and a lyrical flow that could've twisted even Beyoncé's tongue all combined to make ''Dirrty'' 2002's certifiable rump-shaker.
''Soar,'' Stripped (2002)
Listening to this inspirational power ballad, it's hard to imagine why RCA opted to allow ho-hum ''The Voice Within'' to bat cleanup as Stripped's final single. Sure, both songs tread the same clichéd believe-in-yourself-girl ground ''Don't be scared to fly alone/ Find a path that is your own,'' Xtina implores on ''Soar'' and yet, where ''The Voice Within'' sounds like it could have been mined from Aguilera's 1999 debut, ''Soar'' ups the dramatic ante and showcases a confident vocalist who's not afraid to out-Mariah Miss Carey herself. Wall-crumbling levels of bombast aren't for everyone, but it's almost impossible to avoid the side-to-side sway when the gospel choir kicks in right after the three-minute mark, and Xtina tackles that dog-whistle high note. (Plus, going off on a tangent here: Anyone else notice that if you sing the chorus to Reba McEntire's ''Fancy'' over the closing notes, it totally fits? Nice.)
''Loving Me 4 Me,'' Stripped (2002)
One of the few songs that lives up to the album's title, this slinky, Scott Storch-produced ballad matches one of Aguilera's most restrained, intimate vocals to date with little more than some mellow drums and spacey synths. Her emotional connection to the material makes sense, though, as she sheds her penchant for tackling grandiose ''message songs'' and instead offers a heartfelt paean to an unconditional lover. Even the spoken-word interlude works here, as Aguilera delights in finding a guy who ''loves every freckle, every curve, every inch of my skin.'' Yes, folks, dirrty girls need love, too.
''Get Mine Get Yours,'' Stripped (2002)
On paper, this ode to ''friends with benefits'' might seem to like a teen pop-tart's desperate attempt to prove she's ''mature.'' But spend a minute with producer Steve Morales' wah-chicka-wah synth line and Xtina's sultry-not-skanky request for her man to ''work me like a 9 to 5,'' and we bet you'll be seduced. Mercifully, there's no taint of ''not a girl, not yet a woman'' coyness on this track; Xtina's all woman here.
''Tilt Ya Head Back,'' from Nelly's Sweat (2004)
Before the Baby Jane alter ego fully emerged on Aguilera's just-released Back to Basics CD (and its lead single, ''Ain't No Other Man''), the songbird effortlessly straddled the border between hip-hop and jazz on this rousing duet with Nelly. And whether you're inclined to jitterbug to those jaunty horns or simply drop it like it's hot, there's no doubt Aguilera's playful riffing upgrades the track to must-download status.
What are your favorite Christina Aguilera songs?