Thesis Topic Regarding Movies?

I need to write a senior thesis this year and we can choose our topics and I really want to write about movies. The thing is, it cannot be just a research paper, but must be about a hypothesis...ANy ideas? I was thinking about doing it on Alfred Hitch and why his film making techniques (music, camera angles...) made his movies so scary and unforgettable, but let me know what you think! Plus, I'm not completely sold on that idea yet so if you have any more please post them! Thank you!