Reek of the Unzen Gas Fumes:
This is one of the most sonically extreme bands that I have heard thus far. Hailing from Japan, this bm/grindcore band has been producing a quality demos and splits since 2012. They use drum programming, which I know that some dislike. However, they take what could have been a negative, and made it a positive by pushing the technology to its limits. The beats are inhumanly fast, and the guitars are aggressive, and the vocals are simply monstrous.
Kristallnacht:
I think that it is time for this band to get an official listing on this thread. While other musicians were employed at various points during its history, Kristallnacht was essentially a one man project. Since the mid-1990s, this French band has produced a series of short (only around ten minutes each) eps, demos, and splits. They are all high quality, and each contain examples of great bm riffs and overall compositions. While Kristallnacht ceased its activities in 2003, it remains one of the greatest bm bands to have emerged from France.