Most of the ones who jumped immediately to mind were already mentioned: Geddy Lee, Bob Dylan, and Tom Waits. I'm surprised that Little Richard, Elvis Presley, and Ozzy Osbourne haven't been listed yet. Maybe I scrolled past them? I'd never mistake anyone for or with David Lee Roth or Bing Crosby.
Michael McDonald - because you can pick him out amongst 3-4 other background vocalists. In a busy mix. Good luck doing that with any other “distinct voice.”
Comments
Michael McDonald
Whitney Houston
Freddy Mercury
Barbara Streisand
Sting
Cyndi Lauper
Adele
Cher
Without question.
•Tina Turner
•Aretha Franklin
Ozzy, Peter Murphy, Gary Numan, David Bowie, Janice Joplin, Grace Slick.
Those are just off of the top of my head.
Also, honorable(?) mention: Tiny Tim.
Johnette Napolitano of Concrete Blonde
you said most distinct... you never said good
https://www.youtube.com/watch?v=WWiGDy0A0Ho
Most in the list are "distinct" in terms of singing style, and "recognizable", but not sso much "unique sounding".