I think Puppets is the most consistent of their big three/four albums.
Kill Em All is more rooted in the punk sound in a way, they refined their style from there. I like bits of it, but it is not as memorable.
Ride The Lightning has Escaped and Trapped under Ice which were weak IMO. Fight Fire with Fire isn't great either. Ride The Lightning is a belter though, obviously fade to black, for whom the bell tolls. Love Call of the Ktulu also, trying to learn on guitar.
Disposeable heroes is just about my favourite Metallica song, and the rest of that album is really tight. Only weakish song is maybe Lepar Messiah. I'm not sure it always has the high points of ride the lightning but it is just so solid an album.
AJFA is a bit of a mess with poor production. Too big a gap between the great songs (Blackened, One, To Live is to Die, Dyer's Eve) and stuff like Harvester of Sorrow, Shortest Straw, Frayed Ends of Sanity, Eye of the Beholder. I quite like the title track but it just keeps going and going.
This new song is pretty tight.