I made it to max level in Vanilla WoW. I never became a huge raider, but I did do some of the higher level instances like Strat, Scholo, etc.
But nothing, and I mean NOTHING in an MMO will impress me as much as my early days running the Dead Mines in Westfall.
Up to this point, everything had been pretty straight forward in WoW. Go here, kill these guys, and most "dungeons" were just caves or abandoned keeps or the like. But then came the questline involving the Defias Brotherhood. This was easily the most ambitious questline in the game up to that point that I had played, taking you all over the areas you've been and even a few new ones to learn about this mysterious organization that was plaguing Westfall.
This all eventually culminated in exploring beneath the small village held by bandits. After some experimental prodding, I found my self in the caves beneath, but was very much outmatched by the monsters below. This, I thought, was surely the dead mines that I needed a group to clear. But no, this was nothing but the atrium, a prep area for the real deal. I believe I had quests marked "Instance" but wasn't sure what that mean just yet. Having been in Westfall for a while, I saw plenty of messages saying "LFG VC" or "LFG DM" so I assumed that's what I needed to do to progress. I messaged one of the inquiries, and joined a group.
I remember seeing the swirling entrance into the dungeon proper and wondering what that was all about. My group went through and there was a loading screen. This was new. Instead of recklessly running in and killing all the enemies, we had to play it cool, pulling small groups at a time as we slowly made our way through the tunnels. I remember fighting increasingly tough elites, fighitng a goblin in a giant mech in the lumber area, and many more mechanical monstrosities as we descended down to the foundry. I remember blasting a cave wall down with a canon. And when I finally saw the ship, I knew things were about to get real.
We proceeded along the docks, taking out enemies methodically until we were near the boats. We found ourselves matched against a Pirate Cow. "YOU LAND LUBBERS ARE TOUGHER THAN I THOUGHT," he screamed as he stunned us and reached into his treasure chest for better armaments. "I'LL HAVE TO IMPROVISE!" After overcoming him, and climbing aboard the ship, then took down the goblin captain. As we approached the top of the ship, my group members told me the importance of the what needed to happen next.
There was a waterwheel attached to the ship. If you jump on to it, none of the enemies can reach you. As a paladin, with tough armor, magical protection, and healing, it was my duty to get to that wheel in the event of a group wipe. If the group wiped, the whole instance would reset, and we'd have to start again.
Sure enough, the mighty Van Cleef did manage to kill most of my group in the ensuing battle, but I made my escape to that wheel. I sat there as the enemies ran at me in vain, before losing interest and returning to their original spots. My team regrouped. We reorganized. And we took down the Defias Leader. And then for some reason we killed the cook on the way out.
This to me was vanilla WoW. Nothing ever topped that first experience. I probably ran dead mines more times than any other instance in the game, but it was always my favorite. I did appreciate actually beating Gnomeregan with a non-overpowered group (this was a feat in vanilla) and being the last man standing in Zul Farak as we took down a boss hydra, leading me to landing the killing blow and resurrecting my fallen party. But man, those Dead Mines.
