To be honest, this is hard to give an exact answer to the question: which one is the most popular? There are two reasons why. First, because people as much as their tastes differ. Some New Zealand players like poker, others prefer slots only. The casino sites are various too according to the tastes of players. As the saying goes: “You cannot please everybody”. The second reason is that there are too many online gambling sites that it is indeed difficult to choose only one, or even five.
There is only one solution: recommend several online casinos that are popular enough in New Zealand. These mentioned casinos offer many kinds of games, some of them are popular sportsbooks. What is most important, they all are legit and secure. You can try out all of these casinos or just stop at one. But be sure, you will have fun!