8) Superman Works Alone – Batman & Robin
It probably says a lot about the groan-inducing mess that is Batman & Robin that the movie’s most exciting moment is a single throwaway line – albeit one that offers a fascinating hint at a wider DC universe existing on the fringes of the film. Early on in the movie, Robin is badgering Batman in the Batcave about how unfairly he feels he’s being treated. To this George Clooney’s crusader quips: “This is why Superman works alone.”
Whoah, hang on a minute, Batman! You mean to say Superman has existed in the world of this film series this whole time? If only he had flown by Gotham during this movie it would livened things up a bit.
Of course, this one isn’t a full-blown crossover, but it meant a lot at the time, back when the Marvel Cinematic Universe was not even a glint in Kevin Feige’s eye.