Vouch for PNG. I fly with a group in FSEconomy that has operations around PNG, the Solomons, and New Caledonia (shoutout to AUSPAC Air) and it's such a fantastic place to fly. Incredible terrain and challenging bush flight conditions with scenery to boot. Even the hard surface RNP airports are rough; I had to land a Longitude on AYMR at zero visibility and boy, was that a trip. Offset approach right down a narrow valley is gonna be hard to beat on my shelf of "most exciting approaches" for sure.
that's sounds cool ! I've never tried FSEconomy, I did start with Neofly. Is it more fun, more flying with a community? Is this group you fly with open to join?
Yes, flying with a group is really fun - in fact, the community is the reason I stuck with FSEconomy despite its age and it being run by a bunch of dinosaurs who really, really dislike change. Despite it being less flashy and having less features than Neofly or other career MMOs, there's so many ways to interact with the community that other addons simply do not. There's cottage industries for financing or leasing planes, airport modding, livery creation etc that I simply cannot find anywhere else.
And yes, AUSPAC Air is always open. Search for the group on the FSE Forums or Discord if you ever decide to give FSE a try!