6. Slayer - 'Reign In Blood'
1986 was a very good year for thrash metal. That March Metallica released Master of Puppets, and six months later Slayer rose to the challenge by dropping Reign In Blood. The latter is seen now as a heavy metal landmark, but at the time it seemed like a bit of a risk. Slayer had left Metal Blade for Def Jam, and they even agreed to work with Rick Rubin, then known only for his work with rap acts like LL Cool J and the Beastie Boys. It turned out to be a very wise move. Rubin was a metal fan from way back, and he recognized that Slayer had the opportunity to be one of the all-time greats. Reign In Blood sold a huge amount of records back in 1986, and it established Slayer as giants in the world of metal. Three decades later they have yet to slow down or compromise in any way.