Best Christina Aguilera Album?

I prefer her more "bluesy" songs but don't have any of her CDs. Where should I start?
Saw her on the Sandy fundraiser accompanied by piano only. Thought it was great!
Give these two a shot. I think you will like them and you can listen to samples before you buy.
That girl can sing for sure. Let us know what you like.
My favorite is "Back To Basics". It's more soul/jazz/blues/big band style than any of her other stuff.
Yes, the woman has a voice and knows how to use it, what a talent! I've just never paid much attention but the time has come.