Enjoyed reading this. I realise the thread is about old supposedly great albums which have not stood the test of time but I really think it's very often a case of 'you had to be there'.
I accept that good music should always remain good but how many people enjoy music from the 20s, 30s, 40s who didn't live through it?
Current culture and production have a big effect.
I like Beefheart and Zappa but never 'got' Trout Mask. Played often, but just to clear the room, so that's my nomination.
Deep Purple In Rock with my first acid tab was f'n incredible. Timing, situation, circumstance, level of musical appreciation, all have an effect.