Suggestions on eastern 'state' conventions...
Well, Canberra has "cancon" every year at the Exhibition park location on the Australia day "weekend" (more often than not a 3 day weekend) as well as "Wintercon" in winter sometime (Queen's birthday weekend for NSW - June).
Sydney has Leviathan at Easter, Moab in October (NSW labour day long weekend, generally the first weekend).
Melbourne has Arcanacon on the same weekend as Cancon, and Conquest at Easter.
These are the multi-event gatherings, where gamers from many systems converge and play. From 40k to Infinity, Flames of War, fields of Glory, WHFB, Warmachine, etc).
I've met up with folks before at these events and a good time was had by all.
Brisbane has more 'n a few events, too. OzCon coincides with MOAB in Sydney for example.