Thanks to the head-turning success of X-Men: Days Of Future Past, the franchise that Bryan Singer built and then arguably rebuilt is once again a big topic. Though it might not have quite the irresistible traction of the Avengers universe, fans still pour into cinemas in their millions to see X-Men movies, with even the worst two films in the series pulling in relatively major chunks of money, and it's remarkably good to see the quality of the product match the expectations and excitement of the fan-base. Some will still queue up to stick the knife in on the franchise, exaggerating issues on Singer's new sequel, or wilfully ignoring the value in his agenda, because for all of its successes, and its moments of excellence, the franchise has made some serious missteps - not only in hiring directors unworthy of the task, but also in story execution and directing decisions. And one area of the series that has been somewhat notoriously hit and miss is the casting: for every perfectly pitched choice, there has been a Halle Berry - and there's nothing can leave quite as bad a taste in the mouth as the presence of a Halle Berry. With that in mind, we're looking at the very best and the disappointingly worst casting decisions in the franchise so far. First up, the best casting decisions...