^It's not that kind of a list.
It's based on confirmed SS numbers.
Greatest Hits, Doobie Brothers, 2.2 million, not certified
In The Zone, Britney Spears, 2.9 million, yet 3xp
I Am Sasha Fierce, Beyonce, 3.0 million, yet 2xp
American Idiot, Green Day, 6 million, yet 5xp
DOAD is a 1cd album, not 2xp.