If you are interested at all in architecture, Napier (east coast of North Island) was destroyed by an earthquake in 1931. The town was rebuilt in the style of the day, art deco. I went on a walking tour with a guide, and it was great. The concentration of art deco architecture there far surpasses Miami Beach or anywhere else I've been. BTW, there are a fair number of vineyards nearby and an Australian woman on my walking tour had visited several and bought many bottles. When we found ourselves both returning after the tour to look at the menu of an upscale restaurant in a building we had visited, we made plans to eat dinner together in the restaurant that evening. Many restaurants in NZ are BYO so we split a bottle of her wine (I reimbursed her) and had a lovely dinner. This was 25 years ago, so I don't recall the restaurant name.
On the Otago peninsula on the South Island near Dunedin, there are some unusual sights. There is the world's only "mainland" albatross colony. (They only nest in spots with a very high average wind speed.) At that time, you had to make a reservation to watch them from a viewing point. Amazing to watch them try to land to their nesting spot on the side of a cliff.
Not far from the albatross colony is a small colony of yellow-eyed penguins, which I believe may be the rarest penguin species. In the afternoon, you can watch them come ashore and slowly move up to their nests on a sandy hillside.
The Speigt's Brewery tour in Dunedin was enjoyable.
I don't recall visiting any wineries but I biked through vineyards in the Marlborough area on the northern part of the South Island, and in the Napier/Gisborne area on the North Is.
I hiked in quite a few national parks. They're quite varied and all were lovely. My favorite was the Routeburn Track, which at that time you could do independantly at whatever pace you wanted.
If you have any interest in plants, there is a stunning garden in Auckland in a reclaimed quarry. IIRC, it was between downtown Auckland and the airport. ETA: I believe it was Eden garden, and it's a lot closer to downtown Auckland than the airport. I recall seeing some gorgeous tropical rhododendrons in bloom, and a large number of Japanese maples.