I would tend to think either BBQ (because of characters) or Aloha (which is IMHO quite visually interesting). HDDR while my fav show I think might be more appreciated at a slightly older age.
Backyard BBQ is the better as far as the character interaction, but there are a few drawbacks. It's located outside, so if heat or humidity are a factor, then you may want to avoid. Along with that...it will be canceled due to rain if it rains. Aloha is the same as far as that goes.
we did the BBQ with our triplets n what should have been a nice experience turned into a disaster/melt down simply because of the heat/humidity last month.