4. Sam Peckinpah
Here's a director so aggressive and difficult that Charlton Heston even famously threatened to stab him with a prop sword on the set of Major Dundee, and this was after Sam Peckinpah had already lunged at him with one. Think of him as a reverse John Waters; his films are relatively normal affairs (Straw Dogs notwithstanding), but his personality is a picture of madness, with many citing him as being impossible to work with. A notorious alcoholic who essentially drank himself into oblivion, he nevertheless managed to get results, the most acclaimed of which was his classic revisionist western The Wild Bunch. Though the film seems so gathered and impeccable, you wouldn't know it from the director's demeanour; perhaps the most famous anecdote is that when deciding on how to make a horse appears as though it had been shot from underneath, he suggested simply shooting the horse for real.