One

I think this is not only Metallica's best song, but their song with the broadest appeal. It just has this heart-wrenching but very pretty quality to it. Seriously, the first half of the song with the moody, plaintive acoustic and the second half of serious thrash metal just come together so beautifully and majestically. As well, the lyrics are poetic and haunting, with one of the strongest and yet most sympathetic, humanizing anti-war sentiments ever. This would make my top 50 songs ever, easily.