Tick question. EVERYWHERE! I absolutely love New Zealand. Josh and I went there for our honeymoon and it was amazing. While we stuck mainly in the South Island, I cannot wait to see the North Island some day. But New Zealand is an excellent idea for an adventurous destination wedding or elopement. This is for my outdoorsy couples.
I honestly don't know where to begin because there are so many amazing places in New Zealand. But one of our favorite cities in the south island was Queenstown. Queenstown is an adorable little city nestled in the mountains. It's a ski and winter sport destination for sure. The winter weddings here are so magnificent and dramatic. It makes a great starting point for locations to get married. It's also one of the more popular destination locations to get married.
The great thing about New Zealand is that you can hop in a car, drive an hour out of any city, and find some amazing landscapes. It constantly makes you want to stop the car and get out for photos. A hard location to get to, you might love a small elopement in Milford Sound on some kayaks. Be wary that sometimes depending on weather, the kayaking can be canceled. This is definitely something you want to research the right season for.
I personally loved some of the smaller towns such as Te Anau which is a cute little spot nestled next to a large lake. We stayed at a rustic little place outside of Te Anau in a town called Manapouri. Watching my husband try his hand at chopping wood for the fire was a cozy romantic part of our adventures.
Let me know what locations you're thinking about to get married in New Zealand! Or even better, show me where you got married in this awesome country. :)