ANALOGMAN, breath, Dir En Grey, Gackt, Utari, Bump of Chicken, Chiaki Ishikawa, Maximum The Hormone, Asian Kung Fu Generation, The Brilliant Green, Rie Fu, Base Ball Bear, Amplified, Abingdon Boys School, Orange Range, Diggy 'MO, Inoe Joe...
Many more but the rest are mostly composers. I started out listening mainly to anime-intro/outro bands and still do much of the time. But once I branched out I realized the genre and Japanese artists in general have much more to offer than simply being catchy (though I won't deny that in the least, I can't not get into most of 'em); songs are lyrically much more artsy and fantasy-based than any other culture of music I've listened to. It took me a while to open my mind enough to get into some of them (Diggy 'MO, Ishikawa, Joe), but once I did I found something completely refreshing and...'adventurous'(?). Many songs I listen to in the genre are very uplifting and have a sense of 'YOU CAN DO IT! YATTA!'. Which is great for me since most of the English-speaking bands I listen to are very dark and melancholic. I guess I'll shaddup now.