Again, I didn't list the really obvious ones, like RUINS and Afrirampo, since those are all fairly well-known in America, but I really should have mentioned xinlisupreme. They're like Big Black drum machines meets my Bloody Valentine guitar roars with Merzbow doing the mixing or something. I wonder if they will release anything else. That band I mentioned, Blam Honey, does some similiarly cool stuff.
GISM are hilarious; I saw a show of theirs once online at a school. Fucking grand stuff.
I would've probably listed Fuck on the Beach but I forgot they were Japanese
Yellow Magic Orchestra, I heard everything they've done up to a certain point. It wasn't my thing exactly, though it had its moments. Like a synthesizer orchestra with some robot rock as well. I much prefer Denki Groove for that extended 80's electronic sound.
I also forgot to list some more obvious stuff like P-Model and Skyfisher.
Regarding my CD collection: I do have a huge CD collection, I don't really own any non-noise records, and I have 40 whole 100 CD-R case spindles completely filled with CD's (and sometimes I'll put 2 or 3 CD's by the same or similiar bands on the same CD-R, if room permits), and I'm pretty well-acquainted with them all. Keep in mind that I've probably heard 80% of what Tzadik has put out that WASN'T released by John Zorn.
But I didn't copy and paste anything from wikipedia -- hell, I don't think wikipedia even has any info about 75% of the bands I mentioned! I listed all those bands straight from my memory, what good it does me, who knows, because tomorrow everyone will still be like "fuck atsonicpark the asshole".
As for what CD's should be bought in the Japanese market, that's why I tried to list some essentials. Personally, some of my ALL-TIME favorite CD's to come from Japan are.. Number Girl - School Girl Distortional Addict, Bloodthirsty Butchers - Lukewarm Wind, Omoide Hatoba - Black Hawaii, OOIOO - Green and Gold, Boredoms - Vision Creation Newsun, Sparta Locals - Sun Sun Sun, Gaji - Ten to Ten Past Ten, and Limited Express (Has Gone?) - Makes You Dance. So, buy those first.