is it that difficult to search for information nowadays ?
first of all there are a lot bands mentioned within the different dg forums, it would be easy enough to look up more info about those bands whether they are german or not
otherwise i would suggest looking up some german ebm/industrial/goth fan-zines, either in your local (bigger) supermarket/paper stand or online (omg you are on the internet ... already)
most fan-zines have lists of german bands which are not known at all ... hopefully thats not popular and commercial enough for you
once german bands are played on dg it is over for them ... they are becoming known, their cds bought and they are turning into sell-outs !
(insert <sarcasm></sarcasm> tags where appropriate)
and because i have some time to kill (nobody should say im not helpfull)
http://www.orkus.de/index_d.php?siteId=linklisthttp://www.zillo.de/http://www.dmoz.org/World/Deutsch/Kultur/Musik/Genres/Rock/Gothic/ http://www.dmoz.org/World/Deutsch/Kultur/Musik/Genres/Rock/Industrial/http://germany.makaka.eu/music/gothic_and_wave.html (zB #7)
http://www.ebm-radio.de/http://www.klangwald.de/main/bandinfo_index.php