I'm not big on electronic music in general, but I can suggest some music outside of that area.
You've probably already heard of them, but if not, check out Godspeed! You Black Emperor. I guess it would be ambient, but not in the electronic sense. If you can find the time, listen to them while laying in bed not doing anything. It's difficult music to listen to as background noise. If you like them, check out Do Make Say Think. The music isn't as invovling to listen to but it's similar in style.
Also, check out SUNN O))) if you haven't already. You said you were into metal so this may be redundant, but I just want to be sure. Slow, minimalistic, and a little disturbing actually. I used to put this on when I went to sleep and I had some fucked up dreams.
You said you'd listened to all the good metal albums, so again this may be redundant for you but here are some suggestions you may have missed out on:
Hammers of Misfortune: Either The August Engine or The Locust Years, preferably both. It's like the soundtrack to a metal musical, the singing is very theatrical. No growling at all on the album, just very good singing. The music is solid too, sort of in the doom metal style but faster and again, more theatrical.
Beaten Back To Pure: The Burning South is their best work but everything they've done so far is good. Very southern-sounding (southern U.S., that is), but pretty brutal. Also check out: Birds of Prey, the singer's side project. Not as good, but still worth a listen.
The Project Hate: Satanic metal, very heavy. Two singers, a brutal death metal growler (formerly singer of Grave and bassist for Entombed) and an angelic female vocalista. There are electronic elements here as the lead songwriter apparently listens to a lot of dance music, but it's not overt and it doesn't get in the way of the heaviness. Recommend: Hate, Dominate, Congregate, Eliminate, but again the rest of their catalogue is good too.
I could go on about metal all day but I won't. For a change of pace, I'll jump over to...
Hip Hop:
One Be Lo: Awesome MC, great beats. He struggles sometimes with hooks but overall his shit is tight and worth checking out. Bonus: He sings about the struggles of ghetto life without glamourizing violence and misogyny. Intelligence and dope beats == better than the average bear.
OK Cobra: Solid lyrics from Fritz Tha Cat, and the music is fairly unique, very different from your average hip hop/rap fare. I met Fritz after a set he did here in Edmonton at a show where the rest of the lineup were hardcore bands and he's a great guy, very friendly without the massive ego that is common in hip hop. The HxC kids seemed impressed by his music, too.
Optimus Rhyme: These guys get namedropped on Penny Arcade a lot and for good reason. Most nerdcore hip hop is only notable for being nerdy but these guys have some serious skills. They're nerdcore without being total dorks about it, Wheelie (the MC) has some serious skills, and the beats (provided by a live band) are upbeat and incredibly catchy. Listen to it while coding or cruisin in your ride. If you like this, also check out MC Frontalot.
Immortal Technique: Someone you've probably heard of as well. The beats are only so-so but Technique spits lyrics with such force and venom that you can't ignore it. Political (though he does occasionally get into conspiracy theories), but gangsta. If Public Enemy is equivalent to a man giving a speech at a political rally, Immortal Technique is the guy in the black mask throwing a molotov cocktail at the riot police. Angry, intelligent hip hop, worth a listen.
That was actually fairly long. I don't know if anyone will read it but if you do check it out.
