hmm.... well... there's loads, lol.
ok, well, my faves are plastic tree, kagrra,, miyavi and kra...
then you've got mucc, due' le quartz, d'espairsray, 12012, gazette, marusa, kagrou, art school, alice nine, phobia, cali gari, d[di:], shiina ringo, kana, amadeus, kneuklid romance, jinkaku radio, kozi, blood, clothoid doll... yes... there's a lot, lol.
quite a few of them are difficult to find tho, unfotunatly.
o, and the obvious ones, dir en grey, malice mier, x japan, gackt (if you want...) hyde...
there's also b'z and shwartz stine (i've probably splet that wrong) and every little thing... tho they're slightly less what i think you'd class as 'rock'