Vanilla WoW was nearly perfect for me except for a few things:
-Itemization could have been better. "Fistpunch Gorget of the Tranny" was lazy and boring. There was too much loot that didn't matter, and it dropped far too commonly. All gear should be coveted, not sold to vendors.
-There should have been a few non-instanced dungeons that housed desirable, but not essential, items. Rare mounts, cosmetics, rare crafting mats, harvesting nodes, etc. These areas should have been the most challenging in the game.
-There should have been more contested rare-spawns/raid targets, ideally in PVP enabled zones. They addressed this with Azuregos/Kazzak/Green Dragons pretty quickly though. Still... I wish WoW had a few really rare solo camps like Quillmane, Pyzjyn etc.
Aside from that... the game was straight up superior to EQ in every conceivable way.