Bad Santa (2003)

The antidote to every cozy Christmas film. Billy Bob Thornton's Willie is a drunk, foul-mouthed safecracker who takes a shopping mall Santa job each year only to rob the place, and the comedy comes from how little he hides it from the children lining up for his lap. Thornton never asks for sympathy, which is exactly why the oddball friendship with a lonely boy lands without turning sappy. Strictly after the children are asleep: the swearing barely pauses.