My Sunwell guild. I just miss those guys.
I remember working a brutal as fuck factory job during our Sunwell progress and my raid leader would let me take naps and bench me for some bosses because I was so tired. I was also one of the best Shaman healers though (dat Brain Heal) so she had to bring me in most of the time. I just napped at my keyboard whenever I was able to bench, haha. It was a fun guild, lots of laughs and banter. We had a lot of fun and we did eventually finish Sunwell.
I left that guild when WotLK dropped because a bunch of my IRL friends were starting to play again and formed their own guild. That was also quite fun, we did Naxx together. But then the GM decided he was bored with WoW and instead of simply passing leadership he disbanded the guild, so we were all fucked.
It led to more nice times for me though as I switched servers, joined a different guild and progressed Ulduar with them having lots of fun with a very angry German raid leader and a Warrior tank with the worst temper in the world. They were both always so angry it was comical for the rest of us and we somehow managed most of Ulduar's hard modes that way. Then our angry German raid leader got bored with us and left, which led to the guild disbanding.
Then I found a new guild where I actually met my current boyfriend, so that was a whole new chapter. It was one of the best guilds I've ever been in and I even considered them like family at one point (I was having IRL troubles and considered WoW a bit of a refuge). Drama happened and I quit, but I got a boyfriend out of it, so... worth it.
Now I'm in a guild I've been in for 2 years now and enjoying it very much, they remind me a bit of my Sunwell guild. I still look up a lot of old players from time to time that I knew, wondering if they still play and such.. but mostly I am happy with the present and look back fondly on my former guilds and the memories I forged with them.
As for the gameplay itself, I'd say levelling in vanilla and again in TBC were my peak times. I was filled with so much awe at the game and I just couldn't get enough. I miss the feeling of community servers used to have. I still think my server has a little bit of that since I know so many players on it and can easily find them if I run around Warspear, but it's not like it was back then. You could forge a reputation for yourself and everybody would know if you were good or not. I remember my first server going absolutely wild when our top guild killed Kel'Thuzad for the first time. It was by no means a world first but it was still such an insane feat that it was all we talked about for hours. I wasn't even level 60 yet and I was impressed because of how impressed everybody else was. I knew it was a big deal. That was what made me decide I wanted to be a raider. I wanted people to admire me for these things too.
A more specific fond memory is when I was chilling out in Orgrimmar and I found another Shaman from my guild, dropped all my totems and started to /dance. He joined in. Soon we had a lot of Shamans joining our party and eventually around 30+ Shamans were dropping their totems and dancing and casting spells. So I started a Shaman party. Shaman parties are the best.
This got long. I'm clearly a bit bored and drunk, haha!