At my house, we don't let our children watch the same movies over and over (theoretically, at least). We believe that film is a tool to can be used for a wide variety of things, and that this belief should be reflected by exposure to a wide variety of films. It's not that we have anything against multiple viewings, but we try to counteract our kids' tendencies to want to watch the same thing ten times in a row.
Partially, this is because kids (of all ages) can be easily indoctrinated by films, and this risk is increased by the viewing approach that says "I like this movie. I should watch it again."
We also try not to let our kids do much screen watching at all until they're at least a year old. We just want their tiny brains to be somewhat grounded in what the real world looks, feels, and sounds like before we start introducing them to fantasy worlds of any kind.
Both policies have born fruit, I believe, but we have been partially unable to keep certain repetitions from our girls. Sometimes they will wake up before my wife and I do in order to watch a movie they love (although this doesn't happen often) and other times they will see the same thing two or three times while visiting family for a day.
I'm interested to know, what policies do your families follow (if any) in regards to watching movies in a home environment - even if it's not your home? How do they differ for children and adults? What results have you seen?