I love old school Metallica, but their new stuff just doesn't hold up. Therefore, I'm choosing Iron Maiden. Iron Maiden haven't truly commercialized or sold out. They've also made MANY more good albums than Metallica. Both had great albums during the 80s. The difference is that Metallica had 4 and Iron Maiden had 7. Also, I would only rate the first two Metallica albums as highly as I would rate any of Maiden's albums from the 80s.