Sometimes the best way to really discover a place is to buy or rent a car and get off the beaten track. Although a car can sometimes be an inconvenience, especially in cities where parking can be a problem, the independence to discover the countrysde often outweighs any disadvantages.
Although the cost of buying or renting a car is often quite high, especially on shorter trips, this form of transport is much more affordable when split between a group of friends over a few months.
Although it is impractical to buy a car in the smaller Pacific islands, many travellers to New Zealand buy a car there and sell after they've finished travelling. In New Zealand it is easy to buy, register and insure a car and the country is big enough to get value for money.
In other countries in the Pacific region, renting a car my be the best way to get around. Some countries don't have a good enough bus network, particularly if you want to get off the beaten track and you can't beat car (or motorcycle) travel for flexibility.
There is a big choice of rental companies, from the big companies such as Avis, Budget and Hertz along with smaller companies which may give you a better deal if you are keep the car confined to a particular geographic region.