I just stumbled across a website that was new to me that seemed worthy of sharing: http://www.commonsensemedia.org . It consolidates thousands of reviews of movies, books, TV shows, games, websites, and music, with notes about age-appropriateness and descriptions that ought to enable parents to make some judgments about whether the material is appropriate for their own children.
Even better, there are many lists of recommended titles. For example, here are the lists of recommended movies, (without regard to age-appropriateness), including such lists as "Best Offbeat Animated Movies" (Chicken Run, James and the Giant Peach) , "Best Anime Movies for Kids and Preteens" (Miyazaki holds the top five spots), and "Don't Mess With These Movie Moms" (The Incredibles, Spy Kids). There are book lists too, which will help me as I am out of touch with any children's book published after about 1989.
As usual, you can't let the judgment of the editors of any website substitute for your own judgment. But it seems to me this site will be helpful in sifting through the huge volume of media aimed at kids.