"Symptom of the Universe" by Black Sabbath was voted as having the greatest riff of all time by panel of experts at Metal Hammer.
Tony Iommi tells the magazine that back in 1975 when he wrote the song, he was always looking for something to inspire new riffs. He says, "I would always try to come up with more and more inventive ideas -- different tunings, changing the amps, just fiddling about with the guitars really. I would constantly be trying to improve things and change things. I didn’t really listen to other people, just in case I started playing someone else’s riff by mistake.”
Other riffs that made the Top 10 include "Holy Wars...Punishment Due" by Megadeth at number-two, "Creeping Death" by Metallica at number-three, "Run to the Hills" by Iron Maiden at number-four, "Holy Diver" by Dio at number-six and "The Beautiful People" by Marilyn Manson at number-10.