3. Bryan Singer's X-Men 3
Speaking of the X-Men films, let us never forget the time when Bryan Singer (director of the first two films) opted not to direct the third and instead decided to make a little film known as Superman Returns. What we ultimately got was X-Men: The Last Stand directed by Brett Ratner which many fans will cite as the worst film of the franchise (with X-Men Origins: Wolverine not too far behind it). While the film wasn't without its merit it was far from what likely would have been produced if Singer had stayed aboard. Was X3 about Phoenix or about a cure to the mutation? It didn't do either well, and neither storyline served its purpose fully. And Vinnie Jones as the Juggernaut was just... ridiculous. In Singer's version (according to screenwriter Mike Dougherty) Cyclops doesn't die, he goes on to become a great leader. The Phoenix character wouldn't have been resigned to standing and staring blankly in a red dress for the entire time. And overall, things would have made much more sense. Welp, at least we now have X-Men: Days of Future Past to make up for the sins of yesteryear.