My girlfriend Ginny gets taken to the movie theater to see "Fast Five". After a preview for the Hangover 2, a trailer for a movie comes on. A trailer I made of her father and I where I ask her father for her hand in marriage. After he gives me permission, I race off to the theater she is at to ask her to marry me.
http://www.metro.co.uk/news/863558-cinema-trailer-dubbed-greatest-marriage-proposal-ever
What she doesn't know is our familiy and friends are in the theater with her watching the whole thing, along with about 100 strangers ;-)