Before X-Men revitalised the genre in 2000, it was assumed only the very biggest superheroes could work on the big screen. How silly we used to be; now, with a total box office gross in the tens of billions of dollars, the superhero genre has become the dominant force in modern blockbuster movies. Each year boasts multiple tentpole releases featuring spandexed do-gooders, with the genre showing no signs of slowing; in 2014 alone four of the ten highest grossing films of the year have been based on superhero comics. Being so successful, there's naturally plenty of people out there just waiting to see the whole thing collapse in on itself; each marginal waver in quality or audience attendance is heralded as the end of the fad (a fad that's lasted fourteen years and counting). Although the public's love of supers will of course eventually dissipate, that dark day is certainly a long way off; if anything they're getting more popular. Not that there's not been the chance of it all ending. Over the past few decades there have been several films that quite easily could have spelled the end of the genre; terrible movies and box office flops that, had some fortunate circumstances not got in the way, could have stopped anymore superhero flicks getting made. Here are ten of those movies.