Nirvana - "Scentless Apprentice" (the demo version found only on the With The Lights Out box set. The album version is completely different and not so good IMO)
Great song if you want to get pumped up for something. I.E. it blared as i fought RDM Maat. Starts off and all you hear is cobain say "Hey, hey you guys I wrote a song and it goes ... it goes" And then they burst into a raging 12 minute insturmental(sp?) in which he screams inaudibly for about 3 minutes in the middle. Good stuff.