It is very hard to find a decent movie nowadays. Here are some great sources that the D8A family uses to make intelligent choices.
I heard about this gem in New Man Magazine. CCN Movie Guide gives a thumbnail sketch of the movie from a Christian world view. In addition to rating the quaility, this site sports a morality scale.
A secular movie guide for parents. My wife and I figure that if it is safe enough for kids, its good enough for us. Screen It! is a spoilers site. It pulls no punches on describing the content of movies and plots.