I don't think I have just one album that that I hold dear, but I am a big music lover.
Beatles: Revolver, white album, Abby road
Frank Zappa: Freak out, only in it for the money, bongo fury, zoot allures, plus many more
King Crimson: Court of the Crimson King, Lizard, Larks tongues, discipline
Yes: Yes album, fragile, close to the edge
Simon and garfunkel live in new York
Jethro till aqualung, thick as a brick
And a whole bunch more I can't think of this sec lol