What highlights should every traveller include on their trip?

Fiordland National Park (whether that be a nature cruise, overnight cruise or multi-day expedition)
A marine life experience with penguins, whales or dolphins (NZ is home to 3 different penguin species, 5 different species of whales, and the world's rarest and smallest dolphins)
The TranzAlpine Train
A geothermal experience in Rotorua
A visit to the west coast to see the glaciers - while they are still around.

Our personal favourite is getting off the beaten trail and being rewarded by vast open spaces - you may be familiar with these from the latest 'The Power of the Dog' movie. No matter your preferred views - diversity will leave you very rewarded here in New Zealand.