Minus the three years I was in Japan, I've gone to Anime Expo every year since 2000. (2000-2008, 2012-) I've gone to a few other anime cons as well, and went to Anime Conji in 2012 pretty much JUST to participate in their anime swap meet. I still have tons of crap to sell. ^^;
I've cosplayed since 2000, although I currently only have 3 costumes that would fit right now, 2 anime, 1 movie (Thorin from the Hobbit.) I'm thinking of doing a day at Wondercon next month, so I've got to FIX Thorin if I'm going to do that. I'm trying to figure out a new anime costume for AX this year...