Here's an easy one for me:
Jean Seberg in Breathless
The pixie haircut. A simple chic style. A general faraway irreverence for everything that hides some deep fragility somewhere. Probably the main reason why I keep going back to this film over and over again. One of the best female characters ever, and a truly beautiful girl. To see this film is to fall madly in love. I did. The restored print theatrically is beyond stunning.