After the movie "Some Kind of Monster," it was natural duty again by listening to everything from Metallica. And yes, "Master of Puppets" is actually the best album of the band, by far. I think I can tell, because I have a number of years does not belong to all that stuff. Moreover, it is a mathematical certainty. Metallica went through (especially in the 80s) a maturation process, but at the same time took the creativity of the band with growing success pressure. The intersection of these two curves forms "Master of puppets". "... And Justice For All" was already constructed by and in basic plagiarism of its predecessor, "Ride the Lightning" still too immature. The only downside, from today's perspective, the part over long solo passages. (Not to say that fiddling.) But at that time just goes with it. You could not utter a metal album without minute-long solos. - The most important work Metallica