Best jazz or blues female vocalist ever

There are too many good ones to limit it to one...and I agree with all that have been mentioned.

My personal female Jazz vocalist that I listen to nearly every week would be.

Ella, Sarah, Carmen, Shirley, Rosemary Clooney (try the Johnny Mercer tribute CD, Helen Merrill. Believe it or not, Anne Murray did a CD of standards(kinda Jazz, but not realy) a decade or more ago that is quite good....a review from the magazine Stereo Review called her the female Frank Sanatra on that CD.

She's none of the above, but give either of Julia Fordam's first two cd's a try and you'll see why her 19 year old cd Porcelain made Stereophile's "Records to Die For" this year.