There are a lot of great bands that sing in their native tongue. The most I know (and I listen to) play traditional-80's style heavy metal and come from the Eastern Europe or France. Let's mention some of them:
From Hungary
From the early 80's (or even 70's, if we speak for the pioneers P. Mobil) a lot of metal bands have started their career in this country and released very powerful albums. I recommend the first albums from Pokolgép or Ossian to every fan of good heavy metal. The most important hungarian bands are the following - all are active so I give the internet adresses where you can download mp3 and videos.
Pokolgép -
Pokolgep ONLINE
Ossian -
Az OSSIAN együttes hivatalos honlapja / Hírek
Kalapács -
Kalapács együttes
P. Mobil -
A P.Mobil együttes hivatalos honlapja
Pandora's Box -
www.pbox.hu
Obstruction -
www.obstruction.hu
Omen -
Az OMEN együttes honlapja / Hírek
Morpheus -
A Morpheus együttes honlapja
Stress -
Üdvözlünk a honlapunkon
From Russia
I think that many here know about Aria, the "Russian Iron Maiden", who have released some classic heavy metal albums in the late 80's, early 90's (
Îôèöèàëüíûé ñàéò ãðóïïû "Àðèÿ").
Some other worth checking bands from Russia, who have russian lyrics are:
Catharsis (power/neoclassical metal) -
CATHARSIS. ÎÔÈÖÈÀËÜÍÛÉ ÑÀÉÒ / OFFICIAL SITE.
Kipelov (the band of the legendary ex-Aria singer) -
KIPELOV.RU - îôèöèàëüíûé ñàéò ãðóïïû ÊÈÏÅËÎÂ
Master (power/thrash metal) -
.:: Ìàñòåð - íîâîñòè ::. and of course
Kruiz (thrash metal) -
http://kruiz.gaina.narod.ru
From France
Same here. Many good bands at the 80's, but the most of them have split up very early. Only Trust (heavy metal -
www.trust.tm.fr) and Killers (power/speed metal -
SITE OFFICIEL KILLERS) continue until today and release great albums.
The bands that have split up and I recommend are
Sortilege
Blaspheme
High Power
Satan Jokers
Another legendary speed metal band from France, ADX, have recelntly reformed and as I learnt gave some shows in their country.
Ouf, that's for the start, perhaps I forgotten something, but I 'll be back.