The island of Hawaii, that would be my pick especially if raising kids. I would avoid Oahu, for all the reasons I would pick the big island.
I just spent a week there for business, I really could get used to spending more time on the big island. So much to see and do, so much change in everything from climate to terrain as you move around the island. Nice people, lots of transplants. I have actually started looking at housing pricing myself, noting I already have business in Hawaii on all the islands but so far this is the only one that I could see spending lots of time on.
Note that all the other islands could fit on the Big Island.
Cheers,
Todd
From the original Vancouver!