Combining Genres
Many films do not fit neatly into a single genre, so they are classified as belonging to more than one. For instance, action-adventure films combine elements of the action genre (fight scenes, clear cut good and bad guys) with conventions of the adventure genre (far away places, a quest, etc.). The film Inception is a heist film in many ways, but also fits into the science fiction and action genres. The Princess Bride is both fantasy and romantic comedy. Little Shop of Horrors is a horror comedy musical, of all things. For the multiple genres card, make a film that fits into more than one genre. To help you out, check out this list of genres from Filmsite:
http://www.filmsite.org/genres.html
http://www.filmsite.org/genres.html