Sounds like you all want to have the party house (with your 15 seat theaters). I would hate to have to provide all the entertainment for everyone. If you have the theater, you have to get the movies, have the beverages, etc. Sounds like a money pit to me. I would rather have a friend with the theater
If I were to have one thing, it would be a big screen tv. I would like to have a bowling alley or something but I do not want something that requires constant maintenence ($$$) to be thrown at it (cough_dsm_cough). My values are changing to be more practical.