I also agree about the language in Back to the Future, it pushes the age for viewing up a little bit for me. Eight is a pretty good age. A lot of 80s flicks have swearing that sometimes pulls you out of the movie because it it so obviously there just for the sake of it.
I don't recommend Telltale's Back to the Future game for young children either. You basically lie, deceive and manipulate people including your friends and family to achieve the goals :P