Yeah I have issues with that one too...I consider him more country. Also the singer of one of my father's most hated songs ever (the infamous "Rhinestone Cowboy").
Some more to consider...
Ian Gillan
David Gilmour
David Coverdale
Steven Tyler (especially 70's Aerosmith)
Eric Clapton
Jack Bruce
Roy Orbison
Ian Hunter
Jeff Lynne
Joe Walsh
True...Ric Ocasek even said once that if they needed a cleaner, more professional sounding vocal Ben Orr did the singing...Ric did if they wanted a more "quirky" sounding vocal (e.g. You Might Think")
Most of my favorites are probably already listed...but here they are:
Freddie Mercury
Paul Rodgers
Robert Plant
Lou Gramm
Dennis DeYoung
Kevin Cronin
Grace Slick
Ann Wilson
Janice Joplin
Joe Elliott
Gary Brooker
Don Henley
Glenn Frey
Jim Morrison