Kill em All is my favorite - that album just rocks so hard - it's so raw.....you want to turn it to 11. I had forgotten Mustaine was in the lineup.....just incredible.
Seek 'n Destroy, Hit the Lights, 4 Horsemen, Whiplash....
I have an old tape of Dave Mustaine's first demo release after Metallica and it has a song called "The Mechanix" - it's The Four Horsemen sped up about double with different lyrics. The rhythm guitar part must have been nearly unplayable live. It's probably unfindable today.
I was privileged to grow up in the Bay Area in the early Eighties and be "friends of friends" with a lot of those guys. My first Metallica show was their first concert after releasing Ride the Lighting, and they were already huge locally. You could see what was coming for them.