While the list is probably highly debateable, it is interesting comparing it to what it was 20 years ago.
https://en.wikipedia.org/wiki/List_of_best-selling_albums

So the question is - how many of the albums do you own on the lists of 1-8, 9-32 and 33-76.
For a start I will admit to owning 7 of the first 8, and you get no prize for guessing which one I don't have

If anyone else wants to chime in this could be interesting........