The world would be a better place if who was gone?

Do you know someone who just makes life miserable for themselves and others; someone who would not be missed or would brighten up a room by leaving?Not really looking for the obvious like some third world dictator or a Hannibal Lecter type but someone on a more personal level.
Not necessarily wanting names (if you do, first name only please) but more interested in what they do to make life so wretched that we all would be better off if they were dead.