I'm with John on the Sunset Coast--TCM is my main source for movies--our cable box has DVR, so I have a fair backlog of stuff to chose from, as well. For our kids, pretty much either animation or musicals. Our little girl is particularly sensitive to violence of any sort, so we have to be particularly vigilant.

There are a couple of online sites where you can download old movies that are in the public domain--I found this out by accident, when I installed a program called Miro, which started automatically downloading them. I've just watched "The 39 Steps", and "Royal Wedding"--the files are small, so you have to watch them in "Dinkyvision", but hey, it's free!