9. Lloyd (Dumb and Dumber)
Sure Lloyd's stupidity is endearing and hilarious, but having him for a friend would be awful. Some people are just too brain dead to deal with. How many times will you think Lloyd trading your best dog van for a cheap scooter is funny? Or, let's pretend your taking a road trip with best pal Lloyd and all of a sudden he just starts an inhumanly long pee into various bottles in your car. Trust me no one likes it when you relieve yourself into random containers in a car. Obviously Lloyd and Harry's friendship works because of their impossible aptitude for dumb-assery, but as a normal person either of them would just be awful to deal with.