Poll: Favorite film with a black woman in the lead role?

It was recently announced that Lupita Nyong'o will be starring in the adaptation of the best-selling book Americanah (????). While black women have made great strides over the years in the film industry, solo (not on equal footing in the lead with a man or a woman of another ethnicity) lead roles for them are still few and far between. Which film featuring a black woman in the lead role is your favorite (minimum 5 stars, 1000 votes)? Discuss the list here