From Halo to Super Mario Bros all video games have non-playable characters. NPCs serve their purpose in filling out a world that would otherwise be void except for the hero and his foes. They make it seem like a living and breathing place, and just like the real world, video games sometimes provide us with jerks, idiots, and just plain nuisances. These are the worst NPCs in video game history (well, some of them).
NPCs are put into games to provide the player with goals outside of the main storyline. These side quests can be anything from a simple run and fetch, to a horrific mission fraught with peril for nothing more than a few gold coins. Some NPCs are worthwhile and provide a welcome respite in the middle of the game, some you even grow to care for. Then there are the rest.
Whether they are floating balls with irritating voices or followers that can't seem to put one foot in front of the other let alone fight off hordes of the undead, these are some of the most pathetic NPCs in the history of video games.