Top 20 vocalists...

[Angrafan]

my favorite singer is probably Anneke from the Gathering.

 

[rcknchairLee]

In no particular order:
Robert Plant
Freddy Mercury
Andy Franck
Urban Breed
DC Cooper
Steve Perry
Bruce Dickinson
Rob Halford
Ronnie James Dio
Sebastian Bach
James LaBrie
David Coverdale
Jeff Scott Soto
Joe Lynn Turner
Lance King
John Elefante
Freddie Cruci
Nils Rue
Les Carlsen
Guy Ritter