Ulver - Bergtatt (similar styles, similar times)
Bathory (definitely pioneered the acoustic interludes and heavy/soft dynamics)
Possessed - Seven Churches (weren't Opeth a Possessed tribute band to start off with?)
I'd also say anything from Morbid Angel's Covenant could be pretty convincingly swapped with Master Apprentices (or at least the intro) with little to no discernable change.
Probably more, but, meh.