6. MacGruber: Rian Johnson & Christopher Nolan
I was listening to Rian Johnson's Looper commentary
track and he mentions that his film shares a gag with the rather wonderful and under-rated Saturday Night Live spin-off MacGruber, now, it's one thing to admit to having watched MacGruber, but it's quite another to remember a specific gag and be proud of the fact that you used it! Christopher Nolan on the other hand perhaps didn't want his love of MacGruber to be made public knowledge, but Anne Hathaway happened to mention his penchant for quoting lines on the set of The Dark Knight Rises during a recent TV appearance.
I can just imagine Bale finishing a particularly tricky stunt take and Nolan booming over the megaphone with glee: "Classic MacGruber!" (Here's hoping for some outtakes)