Okay, Mitochondrion is kind of a less known, underground-ish death metal act from Canada. Besides death metal, they successfully incorporate black and a bit of doom metal into their sound. Of course, they're not the first to do that, but I have yet to find a similar band that occupies my attention as much.
These wicked Canadians (as funny as it may sound) exploit deseases and the occult for their lyrical theme. The riffs are truly monstrous, and are occasionally and subtly accompanied by background black-esque melodies. Solos are not your classic heavy/thrash ones, as they also come from black metal. The drums are constantly changing the pace, pounding those double bass pedals to a pulp and delivering a perfect amount of blast beats. The vocals are fucking apocalyptic deep growls with background screams.
Both albums are pure quality and quite equal as well. I, personally, can't listen to them separately and that says a lot. Get it, it's utterly blasphemous, you'll love it. Trust me.