The recording that likely actually started grunge. Sonic Youth - your favorite band's favorite band. Responsible for a generation of drop D guitar rhythm players.
Here's one I recently discovered. Perhaps of particular interest to @macaronus and @Eeyore. Dutch-folk-viking-heavy metal (The lyrics are clean.) From wikipedia (for the truly curious): Nehalennia (spelled variously) is a goddess of unclear origin, perhaps Germanic or Celtic, Nehalennia is attested on and depicted upon numerous votive altars discovered around what is now the province of Zeeland, the Netherlands, where the Rhine River flowed into the North Sea. Worship of Nehalennia dates back at least to the 2nd century BC, and veneration of the goddess flourished in the 2nd and 3rd centuries AD. And Zeeland is where Mike/Macaronous is from. The song (above) is very Viking-esque... asking Nehalennia to protect the warriors as they sail to unknown places in the mist looking for fighting, women, eternal fame, and beer. (well, a man does get thirsty, right?)
In the heavy metal vein, this guy (he's German, I think Norwegian), is probably certifiably nuts, but he's having a lot of fun with it. And it's waaay better than the original.
My wife heard me belting out this nice old Cossack song with a friend of mine at a party one night. The two of us have very deep voices and I think we sang very nicely together!