Well starting off...
There is rock/metal (my main genre following). There are many out there, probably not as much as there is electronic or unplugged (orchestral/piano etc.), but enough to keep one occupied for a long time, especially if one is into that kind of music. Like in the west there are multiple sub-genres, but that's for you to decide. I'll make a list of ones I know and make the best assumption on what sub-genre they are, because I still can't divide them like others can.
- Crow'sclaw (grunge rock/metal; very heavy lead and rhythm guitars)
- Demetori (Power Metal; every members is insane from lead, rhythm and especially drums)
- IRON ATTACK [IRON-CHINO!] (Neoclassical; they like to use older styles of rock/metal and modernize them. If you are a fan of Yngwie Malmsteen you WILL hear that same style a lot
- Minami (Hard Rock/Metal; A group from the Circle IOSYS. Surprising considering it's... well IOSYS.. the same circle that makes all dem music for a number of those PVs you see such as Cirno's Perfect Math Class or Neki Miko Reimu)
- Foreground Eclipse (This one is... kinda hard to out. They are screamo at times, but even I, a person who dislikes screams for the most part, can find their material to be quite tasteful sometimes. Guess it just has to be the right kind of arrangement)
- Undead Corporation (Similar to Foreground Eclipse. Arrangements can be hit or miss depending on the subjective ear, but on a 7-string guitar their leads sound VERY. VERY nice 90% of the time)
- UI-70 (Similar to Demetori however they tend to go all around. Plus they used to be WITH the members of Demetori until they group split basically into two, so just go and find out for yourself)
- S.S.H.[Saitama Saisyu Heiki] (Possibly one of my MOST favorite arrangers out there. He started remixing some time before Touhou and I've known about this guy before I even started following the series. His style is known to be "Synth-rock" and needless to say they are amazing pieces to listen to)
- Thousand Leaves (To be honest, the only thing I like from this Circle are instrumentals. Rest of them are either pretty much hardcore screams or deathmetal. If you are into either/or give it a listen. Most instrumentals are made from the arranger known as "Bach")
- South of Heaven (All around type of group. Hard Rock, Metal, vocals; whatever. They do tend to be hit and miss, so see what you can find)
- Stratiotes (From a group that, again, occasionally does screams. However their leads and rhythms are actually more than enough to make up for it making some of their arrangements, quite ironically, tasteful. Plus instrumentals)
- Xi-on (Techno-metal/rock; These guys are pretty damn cool. Each arrangement is worth listening to and usually has that beat where you just have to listen to. I Extremely recommend giving this group a listen to. Especially their Nuclear Fusion mix.. a lot say it has a similar vibe to that of Persona 3, which I can agree to)
- Magnum Opus (Progressive metal/rock; Definitely the kind you should listen to if you like prog. However, they can vary in type, but typically they do progressive)
- Kurogane Lab (Speedmetal; When I say speedmetal, I mean it. BPM on most of these tracks are ridiculous at times. Not my thing, but others may like it. So if you do, give them a go. Don't get me wrong though, I still do like a couple of their arrangements, just not a lot)
Well, that's it for now. I'll probably edit this post or make a new one on electronic later. This was a pretty damn long post by itself. If you aren't a fan of rock/metal well be a bit patient. I will get electronic done soon, just not right now. Just remember too, this is just a small chunk of rock/metal groups out there who do arrangements of touhou themes.