I don't have time to think of something terribly original but heres one, about 150 people are placed on a massive ship thst goes on a voyage across the Atlantic, there are various weapons hidden throughout the ship such as shot-guns, bats, assault rifles, daggers etc. they have to kill eachother until only one remains alive. Not to mention they have to fight over food and other resources and attempt to pilot the ship. That would be quite a reality show, I can see TLC airing it now.