I'll have another go - I've done this before somewhere, but some will have changed:
Bach - Solo violin sonatas and partitas. I'd need to think about which violinist, but this would have to be in any top ten.
T. Rex - Electric Warrior. Not the first album I bought (that was The Slider), but this one is marginally better, i.e. just about the perfect pop record.
Joy Division - Unknown Pleasures. I picked this last time, and I'll pick it again next time. It just has to be there. Just a perfect album (music, playlisting, artwork, legend, everything).
Orchestral Manoeuvres in the Dark - Orchestral Manoeuvres in the Dark. The sound of Meols, Hoylake & West Kirby in the late '70s. The realisation that music could be a local thing. Stands up well too, it's a fun album. Obviously one needs an original with the fancy die-cut Peter Saville sleeve.
Gil Scott-Heron. Pieces Of A Man. What needs to be said said with exceptional eloquence. A giant of an album.
Miles Davis - Bitches Brew. Impossible to pick a single Miles album and I'm sure you bastards won't let me take my 71xCD complete Columbia Albums box, and BB is a gift that seems to keep on giving - there's something kind of dark and impenetrable always with new things to be heard.
Marvin Gaye - What's Going On. I just think it has to be here, there is something very special about it.
Boo Radleys - Giant Steps. An album that I missed the significance of at the time as I was kind of too close to understand what it was (I knew them). Reevaluating it a couple of years back really shocked me - it's a bloody amazing album!
Stockhausen - Hymnen. It's just a masterpiece. The more I understand about how he did it the more in awe I am. It is an astonishing thing, just insane.
Miles Davis - Someday My Prince Will Come. As I suspected, one Miles Davis album just isn't enough, and I love this one, but I want the remastered CD out of the 71xCD box as the cut/edit in Drad Dog on the original LP version pisses me right off (and loses a great solo).
Damn, that means I've no Mingus, Monk, Hubbard, Krautrock and a whole shedload of other stuff that I obviously need.