The following itinerary is from the Destination NZ site and in response to the number of requests I get for travel ideas when coming to NZ. It is set up for travel by car with a ferry trip from North to South.
Day 1 , from Auckland travel north and explore the beaches and harbours of the Bay of Islands. Day 2 , visit the historic settlement of Kaitaia and take a day trip to Ninety Mile Beach and Cape Reinga. Day 3 , head south and return to city life in Auckland. Day 4 , travel south through Waikato countryside to the magical Waitomo Caves. Day 5 , explore the lakeside adventure capital of Taupo. Day 6 , drive the remarkable Desert Road in the shadow of volcanoes and unwind in the pretty gardens of Palmerston North. Day 7 , head for Wellington and indulge in the rich culture of the capital city. Day 8 , cross to the South Island and go whale watching at Kaikoura. Day 9 , visit Christchurch city for a little retail therapy. Day 10 , head south to Dunedin and sample the rich heritage. Day 11 , drive through the wilderness of Southland and stop at New Zealand’s southern-most city, Invercargill. Day 12 , turn north, heading for Te Anau and its famous glow worm caves. Day 13 , take a round trip to majestic Milford Sound. Day 14 , head for Queenstown and dare yourself to sample the adventure activities. Day 15 , stop by beautiful Wanaka on the way to Franz Josef or Fox Glacier in West Coast glacier country. Day 16 , head up the coast until you reach Punakaiki and its stunning rock formations. Day 17 , make your way over the Lewis Pass and relax in the hot pools at Hanmer Springs. Day 18 , finish your journey in picturesque Christchurch.
New Zealand has some rather interesting natural landmarks as you will no doubt see as you travel around our fair land.
In the South Island you can see everything from the split apple to the moeraki bolders in the round shaped area and the Pancake rocks at Punakaiki for a different formation completly.
In the North there are some interesting places to see including the fabled rock wall of the Kaimanawa forest or the stone circles near Manganui bluff.
Favorite thing: One of the loveliest things about New Zealand is its unique Flora and Fauna. If you have an afternoon or day to spend in the native New Zealand bush then I would certainly encourage you to do this. You will see all sorts of trees that aren't found anywhere else. The Kauri tree (see the pic) is known as the king of the forest because it stands so tall and mighty. Unfortunately many of these trees were logged in the early settler times so there aren't so many large examples around. You could go and see "Tane Mahuta" in Northland which is on the tourist trail. Native New Zealand trees are now protected so if people have one on their property they cannot remove them without resource consent (which is very hard to get!).