... what? Not "Star Wars"? Not even "The Dark Knight"? (Wait -- that's the 21st.)

See? Cinephiles and music collectors aren't the only ones who feel the compulsive need to make lists. Though, usually, we flaunt the subjectivity of the exercise (and try not to figure box-office popularity into the equation). But not this University of Chicago economist profiled in Monday's New York Times:

Ask David Galenson to name the single greatest work of art from the 20th century, and he unhesitatingly an