Unity Games may not fit everyone's definition of a game convention but it is a great gaming event nonetheless. It is essentially a bunch of gamers getting together bringing their own games and playing a lot pick up games. People bring games to share and they just tag them so they get returned to their owners. No game vendors room and the only organized games are the ones attendees organize themselves. Because there are no GMs/judges, no programs, no event registration, no game libraries to maintain, and no prizes, the overhead is lower. If you pre-register it only cost $12.50, $12 if you pay to one of the local reps.
It is a few months away but there is a good chance I will there for this one.