German - ASP, Rammstein, Oomph, Eisbrecher, Megahertz, Gamma Ray, and In Extremo
Finish - Nightwish and Korpiklaani
Swedish - Freak Kitchen, Hammerfall, Diablo Swing Orchestra
Japanese - Ali Project, Gazette, Yousei Teikoku, and EsitTrace
I still want to listen to more music, I always feel like this list is way too short :x