DH and I (with kids and BIL) went to Hawaii in October 2001 and got married on the beach.
“The book” has one listing for each of the islands. We spent time on two: Kauai and Oahu.
I really liked Kauai. We swam, explored, went SCUBA diving, took a helicopter ride, enjoyed shave ice and went to the spa. It was easy to have fun and relax on Kauai.
I am not a big fan of Oahu. Yes, we swam, went to Pearl Harbor, climbed Diamond Head, went to the Dole Plantation; but Honolulu is just a city on a beach. Traffic is terrible, the local merchants are pushy about selling their junk to tourists, and it is very expensive.
We spent our last night in Honolulu at the Halekulani – and loved every minute of it.