Oh man, that Budgie post took me back...
Another great Metallica cover of an epic song is "The Prince," by Diamond Head. Metallica's version was the b-side of the "One" single in '88, but they'd recorded it a year or two earlier (check out their note below about how they later tried to remix the song but "failed." Whew!).
F*ck the a-side, I wore the f*cking cassette out listening to this thing, unable at the Metallica-obsessed age of 10 to believe they could cover songs that were better even their own. I did this art class project in 5th grade where I recreated the cover (sick Pushead) with watercolors, stippling, the whole nine. If I can find it, I'll scan it in and post it...it was a perfect remake. For now, here's the original and of course, the vids.
(I think they rereleased it later on this "Garage Inc" album, but this vid is the '88 version)