I often talk about the egregore of a place where music is created and how certain geographic locations and the culture imprinted in them influences the music made there. fHere is a snapshot at where the best Black Metal is coming from though at the end you will see there is a catch a country with more appropriation is obviously going to pump out more music if creating content is the key to their machine.
Columbia ,Romania Poland , Ukraine , Belgium ,Australia, Austria, Japan, Greece, Ireland, and Switzerland
The following bands have 2 Entries and 3% of the best black metal. Then the number go up from here.
England & France
I do like more post rock influence black metal that has an experimental edge, so a great deal of this comes from America. also America is quick to jump on band wagons so explains how they edged out Norway, most of their black metal tries to be derivative of what Norway originally did in this genre.