These are some of my favourite J-Rock bands.
Wyse: Air
X Japan: Endless Rain
L'Arc en Ciel: Driver's High
L'Arc en Ciel: New World
The Pillows: Hybrid Rainbow
The Pillows: Beautiful Morning With You
Onmyouza (onmyou-za): Kokui no tennyo
Asian Kung-fu Generation: Siren
Asian Kung-fu Generation: Blue Train