Katy Perry only has 3 albums out and has a song for everything. There's not a song of hers I don't use.
Britney Spears' discography is flawless too, so many different styles and concepts for her albums.

Taylor, J.Lo, Ke$ha, Mariah, and Ciara.

Lady Gaga

Gaga obvi

Gaga, Kylie, Janet, Whitney and Madonna (pre-Hard Candy)

Bye.

Taylor

you need at least 3 albums to be on the list.

Beyoncé, Mariah, Madonna. The only one that experimented constant progression period.

Bey, Mariah, Whitney, Madonna and Gaga, that's it!!

As always, the artists with the biggest fanbases on ATRL lead polls like these...

I voted for Ke$ha, Katy, Gaga and Rihanna.