Interesting thread. I get this kind of feeling when listening to Foxtrot by Genesis. Discovered it as a kid and I did not listen to music much back then, so for me it will always be the reminder of a certain era. It was on a tape, we would play it when we took the car. The album is quite complex in the way it is written, but to me it still sounds simple and reassuring in a way, perhaps because things as a whole seemed simpler. Weird.
Back to The Visitor; I discovered it much later than you guys, so I guess our experience differs a lot regarding its 're-discovery'. The thing that amazes me the most about it is how much of a continuity it is. Even though it is made of distinct songs, it's like one big masterpiece. Along with Contagion, this is probably the most accomplished concept album I know, and it keeps on fascinating me everytime.