4. Casablanca
Casablanca is one of the greatest love stories ever committed to film but also one of the most oft quoted films ever. The movie's script is just superb while the performances are equally as gripping. Casablanca has such an honest and open tone that is one of the main reasons it has stayed culturally relevant since its original release. The film is brilliantly captured in black and white and everything else falls together around that aspect of its cinematography. The honest tone that it employs throughout is a result of the clean nature that black and white allows while Humphrey Bogart and Ingrid Bergmann's performances gain a layer of subtlety thanks to the a lack of colour. This layer of subtlety helps elevate the narrative above a cliche', tepid romance and into the territory of intriguing drama.