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
Jennifer Warnes
Patricia Griffin
Carrie Underwood
Holly Cole
Madeline Peyroux
Patricia Barber
K D Lang
Bonnie Raitt
Jane Monheit
Thanks for the list so far. I'll research the albums of these singers.

Meanwhile, do you have any great albums (CDs), songs that you can recommend for these singers?
Jeez.. no one mentions Joni Mitchell?! I mean one of the all time absolute greats, ask any of the other artist mentioned who their influences are and I guarantee that they'd all say Joni! And for the OP, which Albums.. sure Blue, Court and Spark, For the Roses, all are amazing.
Eva Cassidy Live at Blues Alley
Madeline Peyroux Dreamland
Patty Griffin Children Running Through
Eva Cassidy Live at Blues Alley
Jane Monheit Over the Rainbow
Few more favorites I need to mention:
Ricky Lee Jones
Carly Simon
Carol King
Pat Benatar
Ann and Nancy Wilson
Sara Bareilles
Gloria Estephan
Natalie Merchant
Anita O'Day
Uta Lemper
Lisa Stansfield
Diane Schurr