Feytalist beat me to recommending Folkearth, so I'll second it. They're partly folk metal, partly other. I like 'em, but they are hit n' miss. Wolfsong in Moonlight (Fenris Unbound) is absolutely NOT folk at all, but it's right up there as far as my favorites by them. Also, Rhyming with Thunder, but I imagine it's not for everyone.

Nordman is probably very folk metal. Swedish, I believe. I can't understand a single word he's saying, but he seems very passionate about it, whatever "it" is that he's singing about. Still really like it.

I can't provide links, because I can't get to youtube from here; it irritates me no end when someone offers up a link to it, and it could be interesting. I will cease to be irritated by it after November rolls around though.