I like Gorgoroth, although I've never found anything particularly original about their stuff. It's like a fusion of all the usual suspects, done really really well. I think one of the problems facing ('True') BM is that it's so clearly defined. There's very little space for musicians to really move within it. Xasthur is one of the more innovative names currently working in the genre, but even he's too closely bound up with the Burzum sound to really be able to push things forward to any significant degree.