Flixster - Share movie reviews and ratings with friends.
Letterboxd - Letterboxd is a social site for sharing your taste in film, now in public beta.
Filmsomniac - Filmsomniac.com | TV Tracker | Movie Tracker
TMDB - free movie database
IMDb - Internet Movie Database
TasteDive - TasteDive recommends similar music (musicians, bands), movies, TV shows, books, authors and games, based on what you like.