Internet Movie Database (imdb)
A database of information on over 420,000 feature films, television shows and movies, direct-to-video movies, and video games. Includes movie credits, filmographies, biographies (of directors, actors, writers, etc.), plot summaries, quotations, and trivia. Reviews are linked at the bottom.
Metacritic
Compiles critical reviews and assigns each movie an overall score.
Movie Review Query Engine
Links to reviews from a wide variety of newspapers and magazines, including Variety, The New York Times, The New Yorker, The Times of London, and Entertainment Weekly.
Rotten Tomatoes
Links to both professional and amateur reviews. Gives an overall critical and audience rating for each movie.