In the battle between Christina Aguilera and Britney Spears -- and we're not at all implying that there's any sort of rift between the two pop princesses -- we go for Aguilera, simply because she has a better voice (Britney's is all studio tricks). "Genie in a Bottle" has a slight edge over ". . . Baby One More Time" as our favorite teen queen pop song from the summer of '99 (it's more tuneful). And Aguilera's self-titled debut album, released last year, is just a wee bit more consistent than Spears's two albums (though we'd prefer to leave all of them to the kids, and just take the singles). Still, the former Mouseketeer does tend to overdo it on the vocal acrobatics. Coming from the same school that brought you Mariah Carey and Whitney Houston, Aguilera graduated with the belief that turning every single song into a show-stopping extravaganza is the only way to deliver it. Too bad, because she's got talent. She just applies it a little too heavily (though she does claim that her next album, due later this year, will be more street savvy; that's one way to quash those Star Search theatrics). Aguilera's first big tour caps off a mighty big year: a Grammy for Best New Artist, a nearly seven-times platinum album, two number one songs, and a name-check in Eminem's latest single. Expect Aguilera's hour-long performance to include loads of fancy dancers and all the hits, plus a cover of Etta James' "At Last" . . . just to show that not everything the girl wants is candy-coated.