The classics are classics for a reason. Go first to the names that everyone trusts - Con-Dom, The Grey Wolves, Ramleh, Sutcliffe Jugend, Atrax Morgue, Brighter Death Now, Whitehouse*, MB, Mauthausen Orchestra, Le Syndicate, Genocide Organ, SPK, etc. - I promise you, whether you branch out from the originals and best or not, if you have a taste for Power Electronics, you will never be disappointed. Listen to them, absorb them, understand them. To quote the Satanists, "here is bedrock" - anything else is just pure bonus. And that's not to deny just how great the bonus can be, but you have to have your meat and veggies before you get a taste for haute cuisine, and the longer you stay with this genre the more you discover that the meat and veggies are delicious enough for any appetite.
Seriously, all these projects will give you a lifetime of sordid pleasure. And you want that.
Personal additions - Streicher, Bizarre Uproar, IRM. These I would rate as highly as the originators, but horses for courses.
(*Have to admit I've never been a Whitehouse fan personally, but I've never denied their importance in the field).