1. Casablanca (1942)
This film is considered by many to be the greatest screenplay ever written. The dialogue in Casablanca is better than any other film I have seen. There are so many classic lines in this movie. From “Here's Looking at you, kid” to “I think this is the beginning of a beautiful friendship,” this movie is just dripping with brilliant dialogue. Humphrey Bogart and Ingrid Bergman both bring the dialogue to life with excellent performances. However, it's not merely the dialogue that makes this film great. It also contains an excellent character study and an intriguing love triangle, all on top of the political tensions of World War II. The shadowy film-noir style lighting and cinematography add even more to the drama and emotions. As time goes by, this movie remains superb.