I unfortunately don't remember specifically how I landed here. I do know it was early on, and that I began participating quickly, and that I quickly fell in love with the place.
Winning a TiVo
MetaFilter was always a great place to spend time, find interesting things, and be part of a community. (I'm not a regular on the site these days, but I am still here, and I still feel like I'm part of it, which is pretty amazing.)
Every once in awhile something interesting would pop up that really made the group participation resonate in a positive manner. Those moments stand out for me, even the ones I read as a lurker, like the group's takedown of the Kaycee Nicole hoax, or more recently, how the community selflessly helped save the lives of strangers who almost fell into a human trafficking trap.
On a more personal and fun note, I still recall with a smile the free TiVo contest that scores of MeFites entered. I saw the link and applied thanks to MetaFilter, and (like everyone else) I promptly won my TiVo. Which I didn't want, actually, and sold on eBay for a small fortune back in late 2000. Participating in and winning a contest by being creative and funny, alongside my closest Internet friends: what could be a better community experience than that?