Queen Latifah (if you havent heard her Dana Owens Album, you're missing out!)
Reba McEntire
Ella Fitzgerald
Nina Simone
Nora Jones
Hapa (hawaiian)
Keali'i Reichel (hawaiian)
Diana Krall
Donna Summer
Barbara Streisand
Doris Day
Jane Monheit
Israel Kamakaiwaole (Braddah Iz - hawaiian)
Wynona
Bonnie Raitt
Bette Midler

Lots of classics and jazz, I know. There are others, but there aren't too many contemporary "singers" who really jump out at me.