It doesn't necessarily have to be a metal album, per say.
Mine would be "The Undertake" by Funeral Diner. It's an awesome album but it's not a metal album.
I've been listening to this instrumental, created by a dsbm band called happy days, religiously. I'm a fan of the acoustic transition, thoughts?
https://www.youtube.com/watch?v=gTeJJVZiX1U
oh i completely agree, the only metalcore i listen to are generally bands like converge or shai hulud. modern metalcore is neither "metal" nor "cor" to me.