Barcelona: The undisputed champion from when I first saw Taylor Nichols doing the jitterbug to Benny Goodman while reading the Old Testament, a scene which I watched, rewound, and then watched again immediately. For a long time I was not so fond of the third act, which seems to belong to a tonally darker film than the rest of it, but it's really a tight character study that is incomplete without it.
Casablanca: steals the "play the Marseillaise over German officers singing" bit from Grand Illusion, but otherwise the best of the non-auteur studio films.
The Apartment: The only optimistically tinged Billy Wilder film? Cynicism and compromise, out of which comes something that's neither. Baxter's little 'Robinson Crusoe' monologue is the best:
My Dinner With Andre: Mostly known as "that movie where they just talk for two hours." But it's masterfully composed, with Andre's stories in the first half starting out funny and moving so gradually into subtler and sadder emotions that the viewer is unlikely to notice it. The second half moves on to lighter topics like how to live in the modern world and what it is to try and know someone else. What's more, the film is one long crescendo, with the strongest ideas and dialogue saved for the very end. It would be hard to imagine a more insightful meditation on what it means to be an adult.
The Life and Death of Colonel Blimp: aka "the WWII movie Winston Churchill hated for being too sympathetic to the Germans," all the more impressive for a film actually made during WWII. It has Roger Livesey and Anton Walbrook, two of the four actors who serve as a sign of at least minimal quality in a film, and both play the comedy and drama well. It's also subtle: when the German officer played by Walbrook is attempting to emigrate to England during the war, he gets a speech in which he is asked to explain why. His wife was English, he says, and when she died, his sons, both ardent Nazis, would not attend her funeral. There are many ways to portray what exactly was wrong in Germany in the 1930s and 40s, many of them more explicit, to say that basic human decency was lacking, but "creates sons who won't attend their mother's own funeral" says it delicately but unmistakably.