Nobody works in a vacuum - even the greats look elsewhere for inspiration. These are the movies that directors James Gunn, Steven Spielberg, Martin Scorsese, Edgar Wright, David Fincher, Quentin Tarantino, Guillermo del Toro, Christopher Nolan, Wes Anderson and Paul Thomas Anderson have cited as their favourite films.
From the obvious (it's no surprise that Hitchcock features on most lists) to the obscure, via the left-field (who would have thought Paul Thomas Anderson was a big Adam Sandler fan), these are the films that inspire and influence some of the greatest directors working today.