Marvel Comics I very casually collected in the 80s:
(I collected multiple issues of these:)

(I had these notable single issues, too:)


(Oh, and this oddity from Marvel:)
I was not a comic book kid, really. Spider Man was awesome, and I got my fix first from Electric Company and then Spidey and His Amazing Friends. Later, I was into Spider Ham because it was basically the Weird Al Yankovic of comic books.
But Marvel Universe… THOSE I practically obsessed over. I never got the whole collection, but I pored over the issues I did have with a nerd-tensity otherwise reserved for the stat blocks on the back of a Transformers box or a Lego instruction book.
It was like having all the stories at your fingertips, written out, character-by-character, in plain prose. Which characters were rivals? Who were lovers? How did J Jonah Jameson’s son end up being a wolfman in an astronaut suit, again? That was the ideal method for me to absorb that modern mythology of our time. (Now that I think about it, Marvel Universe is to actual Marvel Comics as Edith Hamilton’s Greek Mythology (another obsession of mine) is to Ovid and Hesiod. So maybe at least I’m consistent, if not cultured in the primary sources.)
I think you can get Marvel Universe in a huge hardbound book now, or read about it on marvel.fandom.com. I do sometimes go down those particular rabbit holes trying to mine some deep nuggets related to MCU characters and storylines. But now that it doesn’t have to fit on a single page for each character–now that there’s both infinite space and an infinite appetite for that information–it seems more wanky, more technical, less wondrous. I suppose everything does when you’re not 11 anymore.