I started MetaFilter, so this is kind of tough to answer accurately, but early on before I even bought the domain, I was still searching for a concept and ten years ago for the 2nd anniversary of the site, I showed off early mockups and how I came up with the concept for a multi-user blog.
Getting hugged by the entire world
I have tons of fond memories, going to my first meetup, meeting people years later and finding out they had accounts years before, and getting recognized randomly while traveling, but my fondest memory is the ten year anniversary of MetaFilter.
We kicked around ideas of what we'd do for ten years for nearly two years before the big date. We wanted to make it a shared worldwide affair and several months before the day we built a new site and finalized a plan to list and coordinate meetups all over the world and send out some money to pay for them. We watched the page closely as it filled up with organizers suggesting venues and we were stoked every time a location was confirmed and attendee lists began to grow. It was really going to actually happen. I came up with a plan and budget to send $50-100 to every organizer to try and help out with bar tabs and I lined up the local Eastburn bar's backroom for a large anniversary party in Portland, Oregon.
The weekend arrived and since Portland's meetup wasn't until Saturday night, by Friday we were already seeing photos and hearing stories of meetups in Asia and Oceania. The European meetups were going well and reports were coming back by Saturday afternoon my time, and I spent most of the day on a long 60 mile bike ride in the heat of summer so I headed up to the Portland meetup looking forward to some rest and relaxation.
I saw a crowd of friends out front smoking and made my way to our back room. The food was starting to arrive and there was ample beer. I brought a bunch of leftover tshirts to give away and at one point there was a slideshow going and we got a microphone and people starting talking about MetaFilter. I looked around the room and saw dozens of people so incredibly happy, celebrating something they loved, something that made me very proud to have created and been a part of. Two years of planning, months of legwork, and we were finally there enjoying it ourselves and getting to listen to everyone's fondest memories of MetaFilter. Many of the stories I heard that night moved me nearly to tears and when I watch pb's video of the evening I still get goosebumps and my eyes well up a bit. At some point that night I got the mic and could barely maintain composure while saying a few words of thanks. I drove home hours later and collapsed, exhausted physically from riding many miles on a very hot day, but also exhausted from all the joy I got to experience and share in that evening, and also to a certain extent, all around the world.
My thanks everyone to who took part that year, that night, and thanks to everyone that took part in this year's sharing of stories as well.