Letterboxd - Letterboxd is a social site for sharing your taste in film, now in public beta.
TMDB - free movie database
Taste - Get movie suggestions based on personal taste.
TasteDive - TasteDive recommends similar music (musicians, bands), movies, TV shows, books, authors and games, based on what you like.
Itcher - Movie, book, music & game recommendations you'll love
MovieLens - MovieLens helps you find non-commercial, personalized movie recommendations.