I just saw this documentary about Norwegian Black Metal today and found it rather good:
It is actually quite meaningful. It has some strong points and perhaps some weaker points compared to TV programs I have seen about the same subject. The possible weak point is that there are rather few people actually telling the story in this movie, why did they not interview more of the central figures? On the other hand these are the ones that usually do not speak to regular media (for a very good reason). Recommended.