To be honest, asking these kinds of questions in this forum will not get you far. The majority of answers you get will refer to more accessible bands and unfortunately that is pretty much the extent of knowledge you will find in the Opeth forum. Also, too many people are influenced by their love for Opeth, which will distort the answers furthermore.
Skip this forum and head over to this thread in the main forum. It's the only place worth hanging out in UM for serious Black Metal.
However, if you're only just getting your feet wet, and I suspect you are, then the Opeth forum is an ok place to start.
You are right there I am getting my feet wet with the serious side of BM. I am more interested in the stuff that is not like Darkthrone (apart from Soulside) and Burzum. I know it sounds bad and yes I really should really try harder with these bands the production just grates on me too much, I understand the reasons for it but I have come from an audio background(I worked in a high end hifi store from the age of 17 and have done it several times in my 30 year existence).
As I have mentioned to before I have been getting into Negura Bunget and Xasthur, so I am thinking along those sorts of lines. I am trying to broaden my listening at the moment as I can not seem to stop listening to sludge/doom/stoner/drone bands atm. BM is a good way to mix it up. Keep in mind that I do alreadylisten to bands like Borknagar and Dark Funeral etc. I must admit I went to the Satyricon show and had a bit of laugh at some of the more motley crue moments but I am really starting to enjoy them and listening back I guess I enjoyed the show as well. There was a really long track they played around the 9 min mark any idea's what that was?