I'm a fan of the ultimate darkness, and maybe like you, I don't find much music that satisfies me quite like I'd like it to. Psy-trance has changed (man) into something I'm not even sure if I like anymore. I'm sure there's stuff out there I would like if I knew were to find it, but most of what I hear is just the same old tired formula and I'm bored to tears with it.
Try this on for size - these guys are about as good as I've found in terms of dark music that is rough as guts and still retains some musicality, and is therefore quite listenable and dancefloor friendly. They play quite a wide range of sounds/genres, but it's all mashed up into a huge heaving monster of doom.
Ancient Methods - Some Strings Attached
As for dark psy. The best dark psy set I ever saw was from Xenomorph. I have his albums though, and I don't listen to them much, so go figure. It was just something about the set I think (top level Commericial Lounge (Melb) in ummm ... 2005 maybe). Redline is/was (?) a local (melb? maybe syd, not sure) DJ who played some great dark psy. No idea if he's still around, he was affiliated with Tribeadelic I think. Loved that guy, he fucken rocked it, I have fond memories of a Logic Bomb gig where he played after them and totally destroyed the place and then Ozzy brought it home in the morning, it was a killer night.
As for dark music in general (and quite a ways away from hard dance), here's some music that I consider to be top shelf darkness (I'll list some albums):
Amon Tobin - Out From Out Where
Future Sound Of London - Dead Cities
Kangding Ray - Automne Fold
and this is more techno oriented, dark, rough, rocking, good shit.
British Murder Boys (in general, this is Surgeon and Regis as a duo. Also look up Sandwell District)
Morphosis
Traversable Wormhole
CLR Records (Chris Liebing, Tommy Four Seven, Monoloc, ...)
Perc (PercTrax Records)
Lucy (I love this guy, really atmospheric minimal techno stuff, I'd mention more like this but I'm not sure it's what you would be after)
Here's a cool Liebing remix of Tommy Four Seven
there must be some mistake I didn't mean to let them take away my soul am I too old is it too late
my
soundcloud my
last.fm