I found MetaFilter, well, AskMe really, while googling for the answer to a question of my own. I'll be damned if I could remember what it was. Then I lurked and read and lurked some more. I finally joined because I was positively bursting to tell someone they should go to The Helmand in Baltimore for dinner, and by God I'd do it again.
It's all about MetaTalk, man...
Honestly, the first time I feel like I "got" MetaFilter as a *community*, not just a (very good, don't get me wrong) answer factory was an early foray into MetaTalk. I wasn't the poster, the call-out-er, the call-out-ee, anything like that, but the care and concern given to community moderation made me realize that this place was a Place, you know what I mean?