so just to negate EVERYthing i just said i say metallicas "kill em all"
Pshaw! EVERYone knows there's the one great Metallica album:

Master of Puppets is the second best.
You're BOTH wrong!
There is and was and will only ever be ONE great Metallica album:

Blackened, ONE, Dyers Eve...
This is a metal icon, and showcases Metallica in all their metal glory. It's angry, it's introspective, it's powerful.
I would rate
Master of Puppets as second best, only by a slight margin.