Favorites can wax and wane, but there are a few albums in my collection that I can't recall a time when I could say "I haven't listened to that for a long time" since I bought them in the 70s (or '81 in the last case). There are others, of course, but I can honestly say I've never tired of these over 40+ years of listening:
Close to the Edge
Nursery Cryme
Foxtrot
Animals
Discipline
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