Easily, my favorite foreign film is Jacques Prevert's The Children of Paradise.  Luckily, it's also a very long film, but it leaves so much room for interpretation and, dare I say it, inspiration.  The acting, for one thing, is probably the best you'll find in any other film, then or now: Barrault is especially brilliant as Baptiste, the speechless wisp of smoke in love with the all-too corporeal Garance.  An incredible film, unprecedented, miraculous!