Ninotchka

On DVD. 

The tagline for Ninotchka, released in 1939, was simply "Garbo laughs!" That's all they needed to sell the movie: the novelty of the solemn dramatic actress in a comedy. Even today, the famous scene in which Greta Garbo's stern character finally breaks down is incandescent. She doesn't giggle in a ladylike manner. She howls, her body bent double, her eyes squeezed shut, her hand pounding the table in appreciation. I don't know how anyone could watch that scene and not laugh along with her.