Who is the greatest METAL VOCALIST ever? SPIRITBOX, HALESTORM, GWAR, more weigh in

Out of all the vocalists in metal history, who is the all-time best? It's a question that's too difficult for us to even answer, so we pawned it off on a bunch of bigwig metal musicians — members of Spiritbox, GWAR, Halestorm, In Flames and more. From Rob Halford to Corey Taylor, see who the pros consider the greatest of the greats.