I'ma pretty big fan of J-rock. Always have been, I definitely favour it over J-pop.
Gazette, Dir en grey (not so much now), MUCC, X-Japan, Miyavi, Due le Quartz, D, Kaggra, , Malice Mizer, Moi Dix Mois, Kana, vidoll, Luna Sea, hide, Plastic Tree, PIERROT, Kirito, Psycho le cemu
and some others