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.

Gentlemen, Thank you for your recommendations. I've been listening to more female vocals lately and this gives me a direction to pursue. Thanks again! Best regards, Stan

Stan, another great vocalist who has not yet been mentioned here is Anita O'Day. If you can get hold of the nine-disc set by Mosaic Records, you'll be in heaven.

Another vote for Sarah Vaughan