What is the best-selling metal album ever?

Some metal albums transcended the genre entirely, becoming worldwide cultural touchstones and selling tens of millions of copies. Which best-selling metal album deserves its commercial crown the most?

1. 1
   Metallica (Black Album)

   Metallica's 1991 self-titled album with over 30 million copies sold — the best-selling metal album in history.
2. 2
   Back in Black

   AC/DC's 1980 album tribute to Bon Scott with an estimated 50 million copies sold, making it one of the best-selling albums ever.
3. 3
   Appetite for Destruction

   Guns N' Roses' 1987 debut that sold over 30 million copies and remains the best-selling debut album in the US.
4. 4
   Hysteria

   Def Leppard's 1987 stadium rock-metal album featuring seven charting singles and over 25 million copies sold.
5. 5
   Led Zeppelin IV

   Led Zeppelin's iconic 1971 untitled album containing 'Stairway to Heaven' and selling an estimated 37 million copies.
6. 6
   Slippery When Wet

   Bon Jovi's 1986 album that sold over 28 million copies with arena rock anthems that dominated the decade.
7. 7
   Master of Puppets

   Metallica's 1986 thrash masterpiece that eventually achieved multi-platinum status decades after its release.
8. 8
   Dr. Feelgood

   Mötley Crüe's 1989 commercially triumphant album that debuted at number one with a string of hit singles.
9. 9
   Shout at the Devil

   Mötley Crüe's 1983 album that broke them into the mainstream and sold over 6 million copies in the US alone.
10. 10
    Bat Out of Hell

    Meat Loaf's 1977 rock opera-metal album that has sold over 40 million copies and never left the charts.
11. 11
    Pump

    Aerosmith's 1989 comeback album that sold over 15 million copies and spawned several rock radio staples.
12. 12
    1984

    Van Halen's 1984 album featuring 'Jump' that sold over 10 million copies and became a defining rock milestone.
13. 13
    The Number of the Beast

    Iron Maiden's 1982 album that launched them to global stardom, eventually selling over 14 million copies worldwide.