Rob Halford would be my choice as mentioned above. Who can possibly scream any better?
Favorite scream in rock?
Robert Palmer lets rip a tremendous, rolling scream near the end of "Sneakin' Sally." "The fact is ... rrrooOOAAAHHHHH .... JUST BEEN CAUGHT."
What's your favorite scream, shout, or yell? Other than Roger Daltrey's, of course.