Building a 100 album vinyl collection 3 must have albums are?

@palasr 

Not sure how relevant that is, as the same could be said for an "original, genuine pressing" of Kind of Blue, Pet Sounds, Allman Bros. at the Fillmore East, Blue Train, etc. As there was no reference to cost in the question and there are always avenues for finding good bargains on anything if one is diligent.

Oh, I forgot.

Crosby, Stills, Nash, and Young: 4-way Street

When an OP clearly asks for 3 selections, why do so many insist on posting a much larger number?  

Impossible...I would personally have trouble with all 100. Still, too much great music would be left out. Good luck with your pursuit.  AB