I've stayed at all these hotels. I would recommend the Kahala first because it is outside crowded Waikiki but is geographically convenient to other attractions on Oahu. The Halekalani is a wonderful hotel but is smack in the center of Waikiki. Ihilani is a resort - once you are inside the property it is quite beautiful but there is not much in the immediate area that you would want to see. Unless the Turtle Bay has been recently updated, I would not recommend it. The rooms, food and service are not of the same quality as the others.