prepare yourself for a long list
Jrock:
girugamesh (awesome live), nightmare, MIYAVI (also awesome live), DIR EN GREY (gonna see them live), HITT, (I used to love An Cafe but now i don't listen them...tho i still love kanon), the GazettE, ayabie, alice nine, VIDOLL, PIKO, GACKT, Dio ~distraught overlord~, 【_Vani;lla】, MUCC, SINCREA, SID, SuG, ALSDEAD, D'espairsRay, L'arc~en~Ciel, Sadie, THE KIDDIE, Rayflower, heidi., ASAGI,
jpop:
girls:
morning musume, c-ute, Perfume, AKB48, mini moni, berryz koubou, W, Kuraki Mai, Hamasaki Ayumi, Utada Hikaru, HANGRY & ANGRY, Ueto Aya, Nakashima Mika, YUI,
boys:
ARASHI, KAT-TUN, NEWS, TegoMass, Hey! Say! JUMP, SMAP, TOKIO, NYC,
other:
ORANGE RANGE, ONE OK ROCK, ON/OFF, ASIAN KUNG-FU GENERATION, cocoa otoko, Aqua Timez, BACK-ON, Nakata Yasutaka (the one who composed most of Liar Game OSTs), AnoHumpty, Teriyaki Boyz, kanon x kanon, KELUN, maximum the hormone, nobodyknows+, AAA, WEAVER, GRANRODEO, flumpool, SPYAIR, Ono Daisuke,
some of those are just the one's i know 1-3 songs but they're still awesome songs