Crack Brain
My favorite v-kei band bar nun. Fast and loud song writing that doesn't sacrifice musicality and doesn't go overboard with medley. Also their live performances look stellar. Shame they disbanded, it was like 90% perfect. Worst part about the band is that the only more elusive task than finding their music is finding live footage. Doesn't help that they made a lot of it either.
I don't know if I'd want all of Madeth Gray'll to reunite but Hisui and Yukina getting back together would be great. I'd jus rather they make music that has more guitar work.