The ultimate test of endurance is probably The Campaign For North Africa game with a listed play time of 1200 Hours with 10 people.
http://boardgamegeek.com/boardgame/4815/the-campaign-for-nor...
http://boardgamegeek.com/boardgame/4815/the-campaign-for-nor...
I'm more a fire in the east type guy: http://boardgamegeek.com/boardgame/8993/fire-in-the-east