John Bergin does some awesome stuff (as himself, or as/with c17h19no3 and other projects), but particular mention should go to his soundtrack for Traitor General available from [REDACTED], as well as the albums Terra Null and Terra Damnata.
He also did a freebie concept album for Games Day (I think Atlanta, but not sure) several years back called Music for Hammering, but that was a limited run promo. It's floating around the net somewhere, but the last I found it was on Pirate Bay, so be wary of malware, annoying pop-ups, etc., assuming that there's anyone still seeding.
Aside from him, check out Nox Arcana, Midnight Syndicate and Corvus Corax.
*EDIT:Well, crud. Seems that Mr Bergin has lost his domain name to a company selling power tools. I've pulled that link, I'll post a replacement as, when and if I find it.