X-Japan is a great place to start.
They have a very epic style to their music, complex with powerhouse drumming, excellent guitar playing, and melodic string arrangements. The lead singer, Toshi, make take some time getting used to though. Once you get used to him though, you'll start to realize that he really is a great vocalist.
WinMX has lots of their stuff, so just type in 'X Japan' and you'll get lots of songs to choose from. For starters, I'd reccommend these:
Art of Life (yes it's 29 minutes long, but it's more than worth the time)
Crucify My Love
Hope this helps. You might also want to check out my latest video (using 'Drain' by X Japan) when it becomes available.