i tend to prefer 1st edition, cuz i think the rulebooks strike that balance between defining enough stuff to where youre not totally confused and dont lose track of how to run your world, and leaving enough stuff undefined so as to leave room for dm imagination.
also, the old rulesets seem simpler than newer ones. a particular aspect i appreciate is the fact that they are "more realistic" (or as much so as a fantasy rpg system can be lol) which allows for my favorite type of scenario, which is a sort of recreation of medieval european society except where all the magic, monsters, and superstition they believed in actually existed, and the world was still mysterious and dangerous. if a world is too fantastical, i feel like its harder to get into, cuz you have no experience to connect it to.