I have to give credit to Amazon for coming out with some metal samplers that introduced me to bands and new genres of music that I probably would have never heard of otherwise. I want to take this time to recommend one of their new metal samplers: Napalm Records All Stars. Sixteen tracks, 71 minutes.
It has a few bands on it that I'm already familiar with from previous samplers and my own investigating, like Arkona and Nemesea. I also learned of two subgenres from this sampler that I previously hadn't heard of: pirate metal and a capella metal.
That's right: a capella. The group is Van Canto, they're from Germany, and here's the video to the song that's included on this sampler. This is so awesome, it makes chills run up my spine. The only non-vocal instrument they use is the drum set. Everything else is vocal.