there are so many awesome ways to kill your sims. in the first one if i had ugly sim children, i would corral them into a room with no doors and let them starve to death. that is what you get for bein' fugly in Heebs' sim world *nods* lol
unfortunately, starving your sim children to death does not work in 2 and 3, so i had to get creative. sims 2 i would lay down an assload of rugs, send in the unlucky sim, have him/her light off a rocket in the house and watch the ensuing flames.
oh, nostalgia *tear*