One of the most surprising albums I've listened to was Baptized in Filth by Impending Doom. I bought it solely on its album art. The production was phenomenal. It all just melded into a wonderful symphony of extreme heavy metal without that blended chaos (cf. Mayhem). I could listen to the entire album and I liked each track. What surprised me most was that I later learned they are a Christian band. Not my cup of tea, but my ears enjoy their sound.