Hello Brian and welcome to the Disney Parks Moms Panel,
Wow! This is a great question and really made me think. My family truly loves both of these options, and it would indeed be difficult for us to choose. I think it comes down to your family and their particular interests.
We often mention that we would fly to Orlando just to have a day at one of the two splash-tastic Disney Water Parks.
Disney's Typhoon Lagoon is our favorite simply because of the
epic wave pool - it is the largest in North America! We can fill an entire day with fun at this water wonderland.
However,
Mickey's Not So Scary Halloween Party is an event that can't be replicated anywhere else. This special ticket event has something for everyone: candy stations for trick or treating, special fireworks, an incredible stage show, and a parade that is unforgettable. So my vote would be for the Party. But, I can honestly say that you can't go wrong with either choice.
Good luck with your decision.
See ya real soon,
Anne