The Hepburn Trinity

Sabrina: Daddy's Little Girl
Roman Holiday: Fun, Vespa-dventures with a hunky Gregory Peck
Breakfast at Tiffanys: Jaded and gorgeous

B @ T wins out for Holly Golightly having a cat named "Cat" --- because she doesn't want to own him or him to own her. And because she redeems herself, quite literally her self, at the end.