A great movie about the Mormon Church is called "Meet the Mormons". It shows about 6 different families from various parts around the world. There is not a preachy, down your throat type of movie, and no full time missionaries to try and ask if they can come and visit after the movie is over. I watched it and thought it was well done and great movie. No, it doesn't talk about polygamy or any of the deep doctrine of the church or why the priesthood is given to men or anything like that. It is best to just show the basic fundamentals of the LDS church and then leave it up to the person after watching the movie to decide themselves if they want to know more about the LDS church.
Here is a link www.meetthemormons.com, in case you can't read it in the picture below, that goes directly to the site to learn more about the movie and can forward to your friends and family. A great way to show the gospel to the world!