One of the advantages of liking who I like, is that they're all dead and you don't have to worry about missing a new album. Well, that's not entirely true, K.D.Lang is stunning and probably the only member of the current generation worth talking about.
My benchmarks, the people I compare the newbie's against are Ella Fitzgerald and Rosemary Clooney. Yeah, Rosemary Clooney, who'd a thunk it but go listen to a couple of her albums. Also, Shirley Bassey can turn in a very electric performance and of course the lady who taught them all how to do it, Billie Holiday.
But if I was being sent to a desert island and was told that I could take the music of only one singer it would be Ella, in my opinion, the best female singer ever. Course it sure would be nice to have a little Sinatra along on that island. The Ella in Berlin album is fantastic and my opinion hasn't changed on that subject in forty years.