Can only be subjective of course - there's no 'correct' answer, but personally love:
What I wrote there /\ is of course the undeniable truth, but as soon as I saw US had posted on this thread, I knew 100% before reading it, that he would state that his choice was CATEGORICALLY the BEST IN THE WORLD EVER.
I think there is little doubt that Karen Carpenter had the greatest ever female vocal. Truly from the heavens.