Suggest one obsure album we all should hear

I love when I discover an album that's new to me, and great.Please share one so we can all broaden our musical horizons.

Mine is:
Wishbone Ash  'Argus'

and I violated the question, which asked for one album.

Well, thanks, everybody, for the list... just mining this list is going to be a lot of fun.

one more, just one:

has a raw "spooky" quality >> Buddy Holly: From The Original Master Tapes

Within the Miles Davis catalog, “Get Up With It” is pretty obscure. And it’s awesome.