Her album I am... could be interesting due to her making the decision to be more hands-on with the composing of her music.
A Best would be pretty neat, too, because of the struggle she went through due to the timing of all of, the stress of being a rising star, and her want for more control. Plus, you could probably find some good sources for it, like the documentary that came out that talks a lot about the time when A Best was released.
