Followed a link from Lifehacker, lurked for several years before finally getting up the nerve to join.
There's been so many posts/comments where I've read it and said to myself "THIS!". I'm not a prolific Asker, but MeFi has helped me move to 2 continents and via other people's questions/posts, I've learnt a lot about esoteric subjects I'd never have heard about without MeFi.
The Russian girls post, banjo, how to dispose of a dead body and anything posted by sonascope are all standouts for me; but what keeps me coming back over the past decade is the sense of family.
MeFi started clicking for me once I stopped lurking and started participating. Then the other users started taking shape and I started recognizing familiar faces.
MeFi is a huge community to me, and as I said in a previous thread, MeFi is my home on the internet.
Big thanks to Matt and the Mods for making this place so special.