Shane Macgowan is the best voice in rock no questions asked. Period. His cover of "And the band played waltzing matilda" is definately the best rock vocal recording ever made. The entire album "If I should fall from grace with god" features the greatest rock vocals ever as he's young and pissed off, he has a brilliant voice, and the alchohol and drugs havent completely slurred him out yet so you can still understand him. But in terms of greats singer ever, it's easily bob marley, he sounds like a prophet of god, and in his home country he even controlled the government with his songs. No other singer has had as much talent and influence as Bob Marley