Most unusual/mesmerizing female voice.

'Weightwatchers online' tv ad singer.

The Norwegian singer Sissel has a voice so pure that it's mesmerizing.

If Sissel's voice is "pure" (whatever that means), so is Celine Dion's and Enya's (and Barbara Streisand's for that matter). I couldn't tell the difference. But she has, or had, a body to die for, that's for sure :)

Listen to Linda Ronstadt sing "Long Long Time" or "I Fall to Pieces" and see if you are not mesmerized.

C'mon, lot's of nice voices and talent mentioned, but none of these more unusual than Eartha Kitt, right?

I'd say pretty uniquely mesmerizing as well.