Heh, used to be funny when you put them in a small room, built a wall over the door and made them keep cooking, then eventually it catches fire and because they can't get out, they just stand there screaming whilst they burn.
Also, make them go for a swim but take away the ladder so they can't get out, eventually they drown.
Or, just stick someone in a small, empty room with no door and just watch them deteriorate.