While Kathryn Bigelow shattered the glass ceiling on the Oscar front, Betty Thomas has quietly become the most successful woman director ever at the box office. Her holiday hit Alvin and the Chipmunks: The Squeakquel is the first female-directed picture to gross more than $200 million. (The former Hill Street Blues actress' films have earned $561.2 million combined, besting both Nancy Meyers' and Nora Ephron's.) ''I like doing movies that are big and iconic,'' says Thomas, ''and not too many girls seem to do those.'' Here are the five top-grossing films directed by women.