Seems that people into dark psy also have great tastes in music outside of dark psy.
I'm into all sorts of psytrance (forest being my favourite, but I like stuff from every subgenre). Other electronic I enjoy: psychedelic chill/downtempo & psychedelic dub, IDM (when it's nostalgically melodic, but the percussion is frenetic and cleverly programmed), some neurofunk d&b, but really, outside of psytrance, I don't really listen to much electronic music.
I really love the atmospheric rock, post-rock and shoegaze side of things, I find this music has the most beautiful melodies that juxtapose the monotone dark psy I like to listen to. Bands like Anathema (I find their death-doom metal terribly boring, but everything after has been truly amazing <3) and Alcest rule my life, big time!!! These bands I could not live without.
Before I got into psytrance, I was a total metalhead, so it's a given that I am also a fan of most styles of metal, from power (:P) to the black metal subgenres and beyond. I too see the parallels between psytrance and metal - the pace is similar, the bass in psy is very similar to the double kick drum, the FM leads sound rather like distorted guitars, the length and atmospheres of psy tracks are very akin to metal tracks, not to mention the intensity...
Those of you into black metal may want to check my depressive black metal band, Lyrinx, out. http://www.myspace.com/lyrinx