One's own preferences in music or drama influence the selection, thus I fail to see that any such lists have any validity.I wouldn't expect anyone to agree with my own list, which changes from time to time.
A few:

Monserrat Figueras
Lollie Anderson
Boris Chaliapin
Alfredo Kraus
Dmitri Hvorostovsky
Maria Callas
Nana Mouskouri
Paul Robson
Joan Baez
Mahalia Jackson
Kenneth McKellar
Edith Piaf
Jussi Bjorling

After listing these, I looked up thread and saw I had a somewhat different list last spring.

Who cares besides me?