What are some alternatives?
When comparing Simkl and Trakt.tv, you can also consider the following products
IMDb - Internet Movie Database
Letterboxd - Letterboxd is a social site for sharing your taste in film, now in public beta.
Metacritic - Metacritic aggregates music, game, tv, and movie reviews from the leading critics. Only Metacritic.com uses METASCORES, which let you know at a glance how each item was reviewed.
Filmsomniac - Filmsomniac.com | TV Tracker | Movie Tracker
Rotten Tomatoes - Rotten Tomatoes, home of the Tomatometer, is the most trusted measurement of quality for Movies & TV. The definitive site for Reviews, Trailers, Showtimes, and Tickets
MovieLens - MovieLens helps you find non-commercial, personalized movie recommendations.