Symphony X is a pretty rare discussion piece when it comes to progressive metal. They do this amazing theme where every album they write is a sort of story with an exposition, a conflict, a climax, and a resolution. They also have little tidbits that kinda tell you more about the growth of those in the story. An example of a song that does this is "When All is Lost." And almost every story has something to do with pursuit of certain ideals or addresses some manner of social concerns. My friend Sean got me into them back in 2008, and he's pretty much the only other person I have seen that knew them well. Hell, I've seen at least two others that like Rhapsody of Fire or Kamelot, at least.
On the other side, you have Combichrist. Zaelis introduced me to them, and only one other person I've met knows who they are right away. Even lesser known is Andy LaPlegua's previous band, Icon of Coil, though he has disbanded that group for a while and just recently got them back to writing material. He also founded Panzer AG. However, I am more of a fan of Combicrhrist. Their music does address social issues, but they also have a habit of just indulging people's dark thoughts. He's also the man behind half of the Devil May Cry 5 soundtrack. He's very much an Aggrotech artist, and he's one hell of a guy. Much like Marilyn Manson, his songs may be pretty harsh and dark, but he's a **censor** good dude. His work varies from time to time, with his latest album (We Love You) full of more Industrial Metal than standard electronic, and his first album having lots of classic Industrial, while he has even experimented with Electro. Hell, even Futurepop and Hard Trance. If you like dark and heavy music in the electronic genre, Combichrist is a hell of a good artist to look up.