You didn’t specify which one. Nancy “The Throat Goat” Reagan it is then.

I like the Unstable Ordinance from Space Quest IV that you can pick up near the start of the game. It’s entirely useless, you can’t ditch it, and if you have in your inventory near the end of the game, it blows up and kills you. Everytime. You have to restart nearly the whole game and resist the adventure game urge to grab everything that isn’t nailed down.