Manned spaceflight for entertainment value
Well terminator salvation has cost around 200million, so if there are five movies that price per year thats a round billion. ISS is reported to cost 100billion, so if it gets de orbited in 2015, and was begun in around 95 it averages about about five billion per year. So it's worth twenty five blockbusters a year for twenty years. I find the ISS more inspiring than any number of movies, but I certainly think privately funded adventures could be a lot less wastefull. I'm not looking to defend the ISS, I made my opinion of it clear before, but manned spaceflight in general can be worth the money for inspiration.