i found this one on netflix. it's called metal: a headbangers journey. it's sort of an anthropoligical/sociological approach to heavy metal. it spans from black sabbath to slayer to alice cooper. they interview everyone from the accessible fans to Gorgoroth, who probably one the evilest person in metal. they cover it all: history, groupies, censorship, glam metal, black metal, church burnings in norway, gender and sexuality, religion and satanism. it's all there. the only flaw i found was that there was very little mention of Metallica. hmmm. after watching it, i think that ronnie james dio seems super cool!