Here is one which I found.

Loudness
http://www.youtube.com/watch?v=PXqBOok0eE0

Sex Machineguns - Think Judas Priest and Iron Maiden but faster. Speed Metal, with some songs bordering on Thrash Metal. Probably my fav. Japanese Metal band. Their music videos are always weird and funny too.

Sex Machineguns - Ai Koso Subete
http://www.youtube.com/watch?v=TXbkpAR6z-g

Sex Machineguns - Burn
http://www.youtube.com/watch?v=menE5G7z_14

Sex Machineguns - Aijin 28
http://www.youtube.com/watch?v=L-ZzzwARpww

Sex Machineguns - Mikan no Uta (live)
http://www.youtube.com/watch?v=LnXUBEJKJtE

Sex Machineguns - Sakurajima (live)
http://www.youtube.com/watch?v=mKEOW27_Wss

X-Japan - The most famous of them all.

X-Japan - Silent Jealousy
http://www.youtube.com/watch?v=WzHbHxSEtVQ

X-Japan - Dahlia
http://www.youtube.com/watch?v=kJsxgQyN9Rk

X-Japan - Kurenai (Live)
http://www.youtube.com/watch?v=CgDdpATtGlM

Sigh - Awesome Avant-garde/Black Metal band.

Sigh- Introitus/Kyrie
http://www.youtube.com/watch?v=tBhQY-Kgwfs

Sigh - Inked In Blood
http://www.youtube.com/watch?v=nsjQ3Suof3kh

Sigh - Death With Dishonor
http://www.youtube.com/watch?v=C5o3JBkakgo

Blood Stain Child - Melodic Death Metal band that sounds a lot like Children of Bodom and Norther with a bit of techno thrown in.

Blood Stain Child - Clone Life
http://www.youtube.com/watch?v=b7EkveEZbmQ

Blood Stain Child - The Road to Ruin
http://www.youtube.com/watch?v=HStZyp93LDA

Blood Stain Child - Truth
http://www.youtube.com/watch?v=-gVvKI3ptCE

Blood Stain Child - Freedom (actually, starting with this album, they switched gears and started sounding a lot more like In Flames with techno instead... )
http://www.youtube.com/watch?v=2oi-8xl7uZ

Galneryus - Pretty awesome Power Metal band

Galneryus - New Legend
http://www.youtube.com/watch?v=zjnNOkjnLVI

Galneryus - Struggle For the Freedom Flag
http://www.youtube.com/watch?v=1I_oi68vxZk

Galneryus - Silent Revelation
http://www.youtube.com/watch?v=rfBI_kmDlNQ

Galneryus - Everlasting
http://www.youtube.com/watch?v=KzAfatAMOQ4

Moi Dix Mois - Gothic Metal. Spiritual successor to VK/Goth rock band Malice Mizer.

Moi Dix Mois - Dialogue Symphonie
http://www.youtube.com/watch?v=UBOldHfxb4I

That's about all I got for ya.