Well, there's the gaming room, where a variety of video games are available to play for the whole con, as well as a room for board/card games, and the manga library for some quiet reading. Although I guess these could be considered official con events...but really, what more would you want other than con events and meeting people?
My first two years of K-con I went alone, but obviously still had enough fun to keep going back. First year was my very first anime convention, so I didn't even cosplay. I just had a lot of fun seeing all the costumes, going around and checking out the events, playing some video games, and chatting a bit with random people. The key thing to having fun is to just get swept up in everything. I'd recommend cosplaying, as it does help you feel like your a part of the con, instead of a random observer. Plus, if there's a photoshoot for the anime you cosplay from, it helps you meet some people. The AMV show is good for about 2 hours of entertainment, if you like AMV's anyway (and who doesn't?). Although I didn't go to the cosplay show my first year, I've learned it's not to be missed because most of the skits are so funny! And some really nifty stuff can be found in the dealers room, so it's well worth exploring.
Considering that two years ago I didn't really know anyone else who was into anime, and now I'm engaged to such a person and have a wide variety of friends and acquaintances who are, all because of the convention, I'm very glad that I went and kept going. It's improved my life greatly!
