This is, of course, a matter of opinion. It also depends on what you mean by “appealing.”
In one way, it is the most developed parts of the Pacific Realm that are most appealing. These are places like Hawaii, New Zealand, and even Guam. These are areas that are essentially modern. They have the sorts of services and amenities that people in the modern world have come to expect. These are also the places that tend to have the strongest economies. Thus, they are the most appealing in the sense that they are the places that most people from rich countries would like to live if they had to choose to live somewhere in the Pacific Realm.
In another sense, it is the remote areas of the realm that are most appealing. These are places like Pohnpei, Kosrae, and other high islands that are not very near to the rich world. These are more physically appealing than many other parts of the Pacific Realm. They have great beauty and are much more exotic than the more modernized places like Guam. These are places that would likely be more appealing to tourists in search of a degree of adventure and novelty.