Lady Diana Spencer's wedding dress. She married a prince and in that dress she looked like a fairy tale princess.
What is the most royal dress you've ever seen? Doesn't have to have been worn by a royal, but just a dress that is so amazing/over the top that if reminds you of royalty?
Can't forget Gone With The Wind!
This one is royal, a royal pain in the butt:
This one from Rear Window. Hitchcock had an amazing flair for dramatic dresses in his movies.