Fun Stuff to Do in Hawaii
I've been to Hawaii twice with my family. We have done several things that I would call memorable and would suggest for your visit.
For anyone in your family that likes history, I would suggest the Polynesian Cultural Center on Oahu (http://www.polynesia.com/).
Another great tourist destination for the history lover would be the USS Arizona Memorial (http://www.nps.gov/valr/), also on Oahu.
If anyone in your family likes the outdoors and nature, I would suggest going to Hawaii Volcanoes National Park (http://www.nps.gov/havo), located on The Big Island.
Two other locations I would suggest for nature-lovers would be Oahu's North Shore (http://northshore.com/), which has great beaches and waves for any surfers, or the Pololu Valley Lookout, on the Big Island (http://www.letsgo-hawaii.com/pololu/), where you can hike down to a black sand beach. This is possibly my favorite location in Hawaii.
There is so much to do in Hawaii, I couldn't just narrow it down to one attraction. I hope my suggestions help. Happy vacation planning! Aloha!