Note: difficulty is partly ranked by which can easily be reached via Star Alliance carriers vs. not as I’m a Star Alliance flyer and this is a list for my own purposes. Country & Territory list is taken from here.
Easy (non-stops)
Hawaiians Islands (nonstop from SFO)(been)New Zealand (AKL nonstop from SFO)(been)Australia (SYD nonstop from SFO)(been)
Next easiest (1-stops)
French Polynesia(Tahiti,Tuamotu, Austral, Gambier) (nonstop from LAX or Honolulu) (been)- Fiji Islands (1-stop from Hawaii, LAX) (planned for 2016)
Guam(nonstop from Hawaii, Tokyo, or via the Air Mike island hopper) (been)- Samoa, American (Pago Pago) (Hawaiian is the only US Carrier that flies in, connect in Honolulu)
- Line/Phoenix Islands (Palmyra, Fanning, Christmas, Canton, Enderbury, Howland) (non-stops from Honolulu and Fiji) (planned for 2016)
- Kiribati (Gilberts,Tarawa, Ocean Island) (non-stops from Honolulu and Fiji)
Marshall Islands, Republic of (Majuro, Kwajalein, Eniwetok)(nonstop from Hawaii to Majuro) (been)- Ryukyu Islands (Okinawa) (flight from Tokyo) http://wikitravel.org/en/Okinawa
- Cook Islands (Rarotonga, Aitutaki, Penrhyn) (connection on NZ)
- Norfolk Island (connection on NZ)
- New Caledonia & Deps. (Noumea, Loyalty Islands) (connection on NZ) (planned for 2016)
- Niue (connection on NZ, but one flight per week)
- Samoa (Apia) (connection on NZ or flights from American Samoa, among others) (planned for 2016)
- Tonga (Nukualofa) (connect in NZ)
- Vanuatu (New Hebrides Islands) (connect in NZ, among others) (planned for 2016)
- Chatham Islands (connection on NZ on Air Chathams)
- Tasmania (connect through Australian mainland)
- Solomon Islands (Guadalcanal, New Georgia,Tulagi) (connect through Australia or Fiji, among others)
- Lord Howe Island (flights from Australia, but tourism is capacity controlled to 400 at any time)
- Papua New Guinea (connect through Sydney)
A Simple Matter of Flights (2+ stops)
Micronesia, Fed.States of (Pohnpei, Kosrae, Chuuk,Yap,Caroline Islands)(Island hopper from either Honolulu or Guam) (been)- Northern Marianas (Saipan, Tinian) (United flies from Guam)
- Palau, Republic of (nonstop from Guam)
- Marquesas Islands (Air Tahiti flight from Papeete)
- Galapagos Islands (flights from Ecuador)
Easter Island(flights from Lima, Papeete, and Santiago) (been)- Bismark Archipelago (New Ireland, New Britain, Bougainville, Admiralty Islands) (from Papua, New Guinea)
- Nauru (national carrier from Brisbane Australia, visa required)
- Wallis & Futuna Islands (fly from Nouméa)
- Juan Fernandez Islands (Robinson Crusoe Island) (small planes from Santiago)
- Tuvalu (Ellice Island, Funafuti, Vaitapu) (Air Pacific from Fiji, but see important note about reliability)
Other Logistics Entirely
- Ogasawara (Bonin, Volcano Island, Iwo Jima) (25+ hour ferry from Tokyo, but runs every 3 days and fares start around $400 each way; alternatively, military history tour operator) Sometimes called the “Galapagos of the Orient.”
Pitcairn Island(long ferry from Mangareva in French Polynesia or cruise ship. Note: ship must be < 450 pax to be able to actually set foot on Pitcairn) (been)- Midway Island (private charters or specially-cleaned ships)
- Tokelau Islands (Fakaofu, Atafu, Union) (no airports or harbors, but there are scheduled expeditions.)
- Wake Island (generally not available to anyone who doesn’t have official US Gov’t business there except for occasional military history tours)