Zack Snyder
Sometimes cameos are not out of choice but out of necessity. In the film Batman V Superman, Zack Snyder was forced to make the smallest cameo possible. When the studio couldn't hold Ben Affleck long enough to have him moving his hands for the camera, Snyder stepped onto the scene (literally). That's some sneaky storytelling. Despite the film earning revenue of 873 million dollars, it was deemed a box office flop.