Three of the biggest females of the 2000's came back in 2008/2009 and slayed the music world like no other. but out of the three eras who had the more successful era when it comes to album sales, single sales, tour gross, impact, achievements, and critical acclaim.
I am... Sasha Fierce without a single doubt. It's Beyonce's peak.
Album Sales: I am... Sasha Fierce >> Funhouse >>> Circus
Singles: I am... Sasha Fierce >> Funhouse = Circus
Touring: Britney >>> Beyonce >>> P!nk (average made per show matters more than Total Gross)
Critical Acclaim/Respect: Beyonce has 6 Grammys.
Impact: Single Ladies alone >>>
