1. I Am Legend
Back when Will Smith still equaled huge box office, he starred in I Am Legend, the post-apocalyptic remake of The Omega Man, which itself was a remake of The Last Man on Earth, which itself was based on the novel I Am Legend (and we're back at the beginning). Near the start of the movie, you can see a movie poster for an upcoming Batman-Superman movie in Times Square, with their respective logos overlapping each other. This was because producer Akiva Goldsman was once working on such a project, but it fell by the wayside. As we now know, in a case of life imitating art (if you can call I Am Legend "art"), Warner Bros. is moving ahead with Batman vs. Superman (or Superman vs. Batman if fans of the Man of Steel have their say). And perhaps the stunt casting of Jay and Silent Bob's Ben Affleck as Batman in the future film is one of Hollywood's biggest inside jokes of all.