I have really been enjoying the evolution concept of this thread.
I seem to know a number of people who got into Metallica via S&M. To me it is a very interesting record - a few songs work fantastically others not so much. However, Metallica is one of the few metal bands that pulled off playing with an orchestra to have the outcome be a very listenable and enjoyable record throughout.
04/05 - Kataklysm, Aborted
04/08 - Carcass, Gorguts, TBDM
04/23 - Behemoth
04/24 - Nile