Just came across this site via Serena Dawson on Twitter. The BFI has some French short movies on DVD with accompanying teaching ideas. In theory the material is aimed at KS2 and KS3, but the one film I watched (via Youtube) could be used with older students.
There is a DVD to buy with all dozen or so shorts, but at least two of them are on Youtube. I watched StrictEternum, a quirky eight minute film with clues leading you to the amusing dénouement. The "lesson plan" to go with it would make sense with, say, Y8 through to Y10.
Well worth a look.