Beyonce: Releasing "Who Run The World (Gurls)" as the first single
Gaga: Relasing "Born This Way", and also making that awful motorcycle cover. And oh being to cocky.
Britney: Releasing "Blackout" during her breakdown. That album would have been huge with the right promotion.
Katy: Releasing "Thinking of you" as a single. Her top 10 consecutive streak would have been longer...
Nicki: Trying to be a pop star
Christina: Bionic
Mariah: Glitter.
Miley: The Can't Be Tamed era.