When I was little my bothers and I must have watched The Swiss Family Robinson close to a billion times. We loved it! I think the idea of living in a tree house is every child’s dream and this movie certainly featured a most spectacular one. (start watching at 5.05 for the tree house “tour”)
There are now some absolutely lovely tree houses out there. This site features some particularly amazing ones. I think the Swiss family tree house will always be my favorite. (I mean, come on, it had retractable stairs to keep the tigers out!) But I could certainly be happy in any of these adventurous homes.
[Some pictures with link to source, but unfortunately some I collected a long time ago and don't have sources for anymore. My apologies!]