10. Kasidy Yates
Pointless love interest for Captain Ben Sisko in Deep Space Nine, Kasidy sort of wandered around the series looking for something to do. Even her captaincy of a freighter and her association with the Maquis, later in the series, and her imprisonment failed to lift her out of the realms of boring, nagging girlfriend-then-wife. There were few storylines (other than the one mentioned above) involving her from which she could not have been excised completely, and the story not have suffered one bit. In fact, they might actually have improved. Go on: do it now. Think about DS9 without her. Would it have been any different? She was like the Cat in Red Dwarf series seven: completely disposable. Even Morn contributed more to the overall atmosphere of the place than she did, and he never once spoke! No, her ship should have suffered a massive core breach and rid us all of one totally empty and unimportant character. Maybe then Sisko might have got some!