Paranoid

Paranoid was not only Black Sabbath's most popular record (it was a number one smash in the U.K., and "Paranoid" and "Iron Man" both scraped the U.S. charts despite virtually nonexistent radio play), it also stands as one of the greatest and most influential heavy metal albums of all time. Paranoid refined Black Sabbath's signature sound — crushingly loud, minor-key dirges loosely based on heavy blues-rock — and applied it to a newly consistent set of songs with utterly memorable riffs, most of which now rank as all-time metal classics.