We are another family that would put Illuminations at the bottom of the list if forced to choose, particularly since it is always there and never really changes other than at Christmas. If any of your family are Star Wars fans then I would say definitely do that show--even my DD21 who is not a Star Wars fan found it impressive as did I, and DH and DS18 really loved it. I had asked on these boards if you could do Fantasmic and the Star Wars the same night and people were right that it would be very hard, especially since crowds would be heavier when you are there. You need to be lined up in front of the Chinese theater building for the show to have its full impact, but if you were flexible about view or didn't care too much about the Star Wars show you might be able to do both in one night. We were lucky enough to do Rivers of Light and really enjoyed it, but I think it might be less appealing to younger kids. I would definitely recommend it, since who knows how long this one will last, but get there early and/or get fastpasses--we had the dining package and so arrived about 30 minutes before the show and the stadium was already closed to standby. We always love the MK fireworks.