There are singers who can really sing and there are those who have a distinctive way of singing.

Singers who really have or have had good singing voices in their day:-

Mario Lanza
Katherine Grayson
Julie Andrews
Tom Jones
Howard Keel
Deanna Durbin
Caruso (think that's how you spell it)
Doris Day
Elvis (although I am not a fan)
P J Proby
Rosemary Clooney
Bobby Vee
Aretha Franklin
Bobby Darin
Christina Aguillera
Andy Williams
Judy Garland
Amy Whinehouse (when she was producing good songs)
Abba girls (Classic trained)
Mama Cass
Nat King Cole
Otis Reading
Marvin Gaye
Dusty Springfield
Connie Francis
Patsy Cline
Dame Kiri
Vera Lynn
Ella Fitzgerald
Edith Piaff
Sammy Davis Junior
George Benson
Paul Robson
All of the three Tenors
Barbara Streisand
Brenda Lee
Bob Marley

Distinctively good (quirky) Voiced Singers:-

Tom Waites
Leonard Cohen
David Bowie
Frank Sinatra
Anthony Newley
Mick Jagger
Rod Stewart (with Faces)
Bob Dylan
Elton John
John Lennon
Liza Minnelli
Lulu
Cliff Richard (for the wrong reasons)
Tony Bennett
Morrissey
Cilla Black (in her hey day)
Diana Ross (had no singing training)
Bing Crosby
Stevie Wonder
Specials
Stevie Nicks
Janis Joplin
Jimi Hendricks
Sugg's
Paul McCartney
Ringo
George Harrison (each of the Beatles because they all were distinctive in their own way.
Lou Reed
Nick Cave
Buddy Holly
Roy Orbison
Kate Bush
Gracie Fields
Vera Lynn
Michael Jackson
Fred Astaire (not brilliant singer but style)
Ozzie Osborne
Axel Rose
Noddy Holder
Frankie Valli

Whatever opinions are on this it is so sad that a lot of the talent is no longer with us.