@Hav_Mor91 Basically you just posted an opinion that you have and anyone who disagrees or challenges it gets a 'corrected' response, that is hardly the idea of a debate/discussion/forum.
Furthermore, I think you fail to grasp an understanding of wider pop culture outwith your own beliefs. My assumption is the average household or 9-5 worker would not label "BOMT" as a classic album. From my knowledge contemporary classic albums include "The Dark Side of the Moon" by Pink Floyd, "Sgt. Peppers..." (Beatles) and "A Night at the Opera" by Queen. However, I do agree that the general public would view the single "BOMT" as a classic.
Here's a summary of how I believe the general public would view Britney and Christina in terms of how they have permeated popular culture and what they are known for:
Britney:
Baby One More Time/School Girl
Oops I Did It Again
Virginity debate/ Justin Timberlake
Toxic
Has kids/ Has meltdown
Comeback-ish/ Womanizer (mildly popular in comparison to other hits)
Christina:
Genie in a Bottle
Chaps/ Dirrty Video
Beautiful
Fighter
Weight gain
Moves Like Jagger (if they even know shes on it)
The Voice (if you live in America)
Okay, argue all you want but try and think through the mind of the average person living in this country not a contemporary music culture know it all. I guarantee you if you stopped someone and asked them about the above, they would mention a few things on that list.