I don't think anyone has mentioned
Norah Jones and
Patty Griffin yet!
Both these women have wonderful voices, though the latter has some incredible lyrics to boot.
Other than that, I think
Billie Holiday was really amazing. Her voice sends shivers down my spines :3
Corinne Bailey Rae isn't so bad either
Joss Stone
Jewel
Rie Fu [hehe]
Amy Lee (not a big fan of her music anymore, but I still love her voice. I remember hearing her in concert. She sounded even better live!)
Mariah Carey has some amazing vocal ranges. Too bad I don't like her that much >.>
Edit: I just realized I missed
Björk and
Enya Shame on me
I just love their voices.
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