I recently heard the abomination that is Amarillo by Brainstorm. I had forgotten how truly awful a cover it is. Then, on the flip side, take The Sound Of Silence by Nevermore. Stunning. I have noticed that metal bands seem to love doing cover songs, some taking particular pleasure in Brittney Spears and Christmas songs. So, a simple question, what would you say are the best and worst cover songs done by metal bands?