That would depend on the music, the song and the singer. I also like Dean Martin, Sammy Davis. Heavens I do believe I am naming the so called 60s 'Rat Pack' That of course also included Frank Sintra. To me, one of the greatest singers, overlooked totally because of his race was Nat King Cole. Another great singer is Perry Como.
You can't go past "Old Blue Eyes" in my book. Even in his death he is still remembered. Although Harry Connick Jnr sounds so like him when he sings. His music is still played at parties and musical evenings to this day.I still watch his movies when they come up on Foxtel channels. I just think he was great. BB
Well, that seems a bit more like an opinion than a fact, all due respect. But on a personal basis, he's right up there in my book as well.
This was mentioned, but not elaborated on: it really needs to be categorized by genre or style. Crooners were a dime a dozen through most of the 20th century, and now the style has migrated and evolved quite a bit. Sinatra was definitely one of the best crooners. Best vocalist of all time is a hard thing to pin down. Stats like record sales could help determine that, perhaps.