Our favorite excursion was Hanauma Bay before it opened. We followed someone else's tip on not acclimating to the time change, which was the best tip ever! We were up early for everthing! We missed all the crowds at Hanauma Bay by arriving at 5:45am and stayed till about 9. We had the beach mostly to ourselves, got in free, and were leaving as hoards of people poured in. I think it was my favorite beach there (the lagoon at Aulani was second.) We bought snorkel gear at Costco there as the rental shop at Hanauma Bay wasn't open that early, and I wished I had bought it at home and packed it...Costco online was cheaper than Costco in Hawaii. Snorkeling in the beautiful morning sun, seeing thousands of fish, and having the place to ourselves was the highlight of our trip. Amazing!! Our second favorite excursion was the Jungle Expedition tour at Kualoa Ranch. It was stunningly beautiful, and our whole family loved it - our teens, our 4 year old, and us! We did not like the Atlantis Submarine at all. The north shore was fun to see too. Would definitely do that again. The Polynesian Cultural Center was just ok....something to do...probably only once for us. Their luau was good - the opportunity to eat poke was awesome! I would try the Paradise Cove one next door to Aualani next time. At the resort, the entire family really, really loved the ukulele lessons and hubby and I loved the morning paddleboard fitness classes. If you get a chance, the spa at Aulani is seriously a piece of heaven on earth. It is worth the splurge, and if you go, give yourself a good 4 hours or more. The spa was a highlight of the trip too!