Nominees for this category are legion. Because metal is not mainstream here, I could name any song I love from any of my favourite bands, but instead I'm going to have to narrow this down quite a bit so we don't get one long, drawn-out post.
On the more obscure (relatively) end of things, I will put an Almora song here, because this Turkish symphonic power metal outfit is probably completely unheard of in this country. And that's a shame, because they are unique and brilliant. I posted about them previously, here, when I posted "Tilsim" as one of my favourite songs. That track comes from Almora's Turkish language album Kiyamet Senfonisi, which, despite my not speaking the language, is my favourite album of theirs. Here is my second favourite song from that CD, "Sonbahar", which I believe translates into "Autumn" and which I would love to hear on the radio over here.