I know lots of bands.
But all my favorites are:
The GazettE, Alice Nine, Dir en Grey, MUCC, An Café, D'espair'sRay, L'arc~en~ciel, Sadie, Kra, Kagerou, Kaggra, 12012, 176BIZ, Ayabie, D, eqlipsE[disbanded], Girugamesh, Gackt, hide, Hyde, LunaSea, Naightmare, Pierrot, Miyavi, Luvie, Merry, Mask, Viored, Phantasmagoria, Plastic Tree, Rentrer en Soi, SID, the TraX, Moi-Dix-Mois, Screw, X JAPAN