I go to a ton of anime and comic conventions every year. Cosplaying is probably my biggest hobby at this point; I've met so many awesome people and have made so many friends. There's really nothing else like it.
I've never dressed up, but I always like seeing all of the other cosplayers. I went to Sydney Comic-Con on the weekend, and overall I don't think the costumes were as impressive as usual overall, but there were some really good ones. Our cons are nowhere near the scale of the US ones of course, so we don't have as much variety. I only spotted one Doof Warrior!
There was also someone dressed as Shia Labeouf from that viral video. He had a green screen strapped to his back, and was walking about doing a spot on impression yelling "JUST DO IT! DON'T LET YOUR DREAMS BE DREAMS!", with the flexing etc. Had the whole damn thing memorized perfectly.
There was also someone dressed as Kung Fury, which was unexpectedly awesome.
Since the main guest was Richard Dean Anderson, of course there was someone dressed as Macgyver complete with mullet wig.
Got my photo taken with Richard Dean Anderson and David Hewlett, both from Stargate. Both great guys who looked like they actually wanted to be there, and went out of their way to make everyone feel welcome.