art, sneakers, watches, guns, houseplants, coins, other random stuff. used to collect legos when i was a kid, might start doing that again since they're really pivoting towards adult fans.
acquiring exquisite shyt, getting a favorable price, intellectual satisfaction from researching the next add to the collection, etc. are cool but it's really all about the thrill of the hunt to me, the rarer the better. i spent probably 200+ hours last year tryna obtain every example in the world of a certain benelli pistol (and the guy who owns the only one that i don't didn't wanna come up off it lmao). it truly is a disease.
edit: misunderstood the op but i guess lego still counts