Popular Female Singers in the past 2 decades


Hi, can you name 10 most popular/favorite female singers (vocalist, artist) in the past 2 decades?

I want to collect the CDs for these singers and very often I heard those songs (mostly pop, movie theme sound track, etc) on radio FM103.5 or 107.9. But I don't remember or recognize their names or the songs.

Celine Dion and Britney Spears are just 2 examples. Thanks.
r0817
Jane Siberry - When I Was A Boy
Ani Difranco - Up Up Up Up Up
Tori Amos - Little Earthquakes
I see Bjork finally mentioned above. I recommend her album titled Serpentine or Debut.
All of the above, plus Natalie Merchant. My wife just bought Adele's "21" album. It's very pop sounding, but not bad.
R0817, what genres of music do you favor? Jazz, pop, rock,folk, bluegrass? That would make recommendations more relevant.