Master of Puppets is by far the best, both the song and the album, though I have mellowed a lot on ...and Justice for All recently, as originally I didn't like it that much. The production is terrible though. It sounds like it was recorded inside a shoebox.
And although I don't like Metallica's post-black album records, I don't really believe they 'sold-out', at least not in the magnitude of bands like, say, U2.
As for bands, I'd say I like Megadeth and Metallica equally, but I don't really like any material created by either band after 1991.