I would definitely do the Halloween party. The fireworks and the Boo to You parade are awesome!! Not to mention that you are able to Trick-or-treat all around the park, plus everyone is encouraged to wear costumes. If you go to the Halloween party, you will not be disappointed. Plus the crowds will be smaller than normal, because of the number of tickets that they sell for the parties.
You can dream, create, design and build the most wonderful place in the world, but it requires people to make the dream a reality" - Walt Disney