4) All The X-Men – X-Men: Days of Future Past
Does it count as a crossover when it involves the characters meeting alternate versions of themselves? Certainly this next entry has the ‘everything plus the kitchen sink’ mentality of a superhero crossover film, so we’re counting it here.
The X-Men franchise’s two distinct eras came together for Days of Future Past, uniting the original cast of Patrick Stewart, Ian McKellen, Hugh Jackman, Halle Berry etc. with the stars of the prequels movies – James MacAvoy, Michael Fassbender, Jennifer Lawrence and co. The result was a film that brought us the best of both differing iterations of the franchise and one that is a lot of people’s favourite X-Men movie.
More of a convergence of conflicting continuities then a classic superhero crossover, Days of Future Past is still one of the most thrilling of all comic book movie mash-ups.