Here's some of the upcoming conventions:
NavCon: Oak Creek, WI – Oct – navcongames.com
Gary Con: Lake Geneva, WI – March – garycon.com
Gaming Hoopla: Janesville WI – May – gaminghoopla.com
Rock-Con: Rockford, IL – Oct – nobleminis.com/RockconWP
Little Wars: St Charles, IL – Apr – link
Fire and Ice: Manitowoc, WI – Feb – fireandiceconvention.com
Midwinter Gaming Convention: Milwaukee, WI – Jan – link
Nexus Game Fair – Milwaukee, WI – June – link
Chaoticon: Green Bay, WI – April – chaoticon.net
NORTHEAST WISCONSIN GAMEAPALOOZA
Northeast Wisconsin Gameapalooza: Oshkosh, WI – October – link
Lets Play Green Bay: Green Bay, WI – October? – letsplaygreenbay.com/letsplay
Gamehole Con: Madison, WI – Late Fall – gameholecon.com
And here's a master list:
link