Good news, everyone! Android (as of 4.1 Jelly Bean) lets you disable notifications on a per-app basis. I'm surprised no one has mentioned this on this thread yet. You'll miss the "it's your turn to Draw Something!" notifications, but, c'mon, will you really miss them?
Settings -> Apps -> Draw Something -> uncheck "Show notifications"
Screenshot: http://www.cultofandroid.com/16833/jelly-bean-tip-disable-an...