I did a comprehensive month-long trip of both islands back in the May 2008 (their winter, so some things will be different for your trip). I'll list first my personal favorites (bold) as well as other places I didn't necessarily love but many people recommend or might be better in summer.

North Island: I loved the north of the North Island. One of my favorite places was Omapere/Opononi. It's quiet and gorgeous. I stayed at a placed called Globetrekkers which was awesome, really friendly. Walk around the whole area on the coast, go sandboarding across the way, and do the Footprints tour through the forest at night (Maori culture and some gigantic trees = win/win). You'll be there at the end of summer, so it will still be nice enough to explore the Bay of Islands/Paihia. Also, Cape Reigna and 90 Mile Beach (you can drive along it if you're careful) is beautiful and go sandboarding!

Auckland is a cool city, of course. Rotorua is so-so (you really don't need more than a day, but the thermal pools in the city are worth a look). Waitamo is similar, see the glow worm caves then move on. Lake Taupo is huge and beautiful and great for skydiving (one of the highlights of my trip in NZ). Neighboring Tongariro National Park is where many Lord of the Rings scenes were filmed and it's supposed to be absolutely incredible (I was there in winter and all treks were canceled at that time, but it is supposed to be unmissable).

South Island: If you're crossing back and forth, I recommend taking the flight one of the ways (not much more expensive than the ferry). The views are spectacular and it's so cool flying across the Cook Strait in this tiny little airplane! Again, in late summer you will be able to do more than I did in winter (the coastal areas in general will be nicer). But my absolute highlights were the following: Franz Josef Glacier (or Fox Glacier) - you spend an entire day trekking up the glacier and it is otherworldly. Your guides are slicing out the steps as you go, and you can climb through blue ice caves and walk between walls of ice more than twice your height. It's breathtaking, not something you get to experience every day. Queenstown is gorgeous and full of fun and exciting things to do. I recommend the Canyon Swing - I haven't bungee jumped but I think this is way better! It's scary but thrilling (you end in a swing instead of bungeeing up and down) and you can choose from all kinds of crazy ways to take off from the ledge. It's usually really cheap to do a second swing too. There's also paragliding, hanggliding, skydiving, and anything else you can imagine. Beyond that, it's a cute town with decent nightlife and really beautiful parks and settings to wander through. Oh, and eat at the infamous Fergburger. It lives up to the hype!

Kaikoura is awesome if you've never gone whale watching (or even if you have). It's a lot of fun and it's probably one of the best places anywhere to see whales. We saw eight on my trip, six sperm whales and two humpbacks! There's also a lot of sea lions around and it's a really small town with some picturesque areas. Only really needs a day. I also enjoyed visiting the Catlins (the southern coast) - you see a lot of wildlife (sea lions, penguins) and it's just gorgeous landscape after gorgeous landscape. And no people. Nearby Dunedin is also good, with a great wildlife tour from there, the world's steepest road, good nightlife (it's a college town), and I believe the Cadbury NZ factory is also there. Milford Sound (or Doubtful Sound) is also a popular place to visit. I imagine if you take some time and do a trek and/or explore the surrounding area (which is insanely beautiful) it would be even better. Otherwise it's a boat ride through the fiords where you'll see some waterfalls, sea lions, kea (mountain parrots), etc. And you can drink the spring water from the mountains - it is the cleanest, crispest, best tasting water I've ever had.

Other places on the South Island (not my favorites but are interesting in their own right and may be nicer in summer): Wellington and Christchurch (both interesting cities, I'd say Wellington has more to see and do), Napier (Art Deco city with lots of vineyards in the surrounding Marlborough region), Greymouth and Nelson (I found boring, but the scenery on the coast is nice and would probably be more to do in summer), Abel Tasman (I didn't go here but I think in summer it would be absolutely worth a visit), Lake Tekapo (it is beautiful and isolated, but nothing much to do except spend some money to go to the observatory - it's supposed to be one of the best places in the world for stargazing, but if you've traveled much you might well have seen better).

If you want to see some more pictures and read a short blurb about all these places (I didn't keep a proper blog then), you can find that here (scroll down to the middle, as it's part of a larger trip including Southeast Asia).

(Below are pictures of Franz Josef Glacier x2, Milford Sound x2, Omapere, a whale in Kaikoura)

Posted Dec 22, 2010

1) Mt. Cook - and splurge for a helicopter trip that lands on a glacier. It's worth it.

 2) Doubtful Sound - everyone goes to Milford Sound, so you can go there if you like to see people *chuckle*. Doubtful is much more remote. Do an overnight on a boat, it takes too long to get there for a day trip. There are 3 boats that I know of, one large and 2 small. Take a small one, it's like having your own personal yacht (with servants). The one we were on held 12 passengers max.

3) Hiking - Guided hikes in 1) Arthur's Pass and 2) from Wanaka to view the Rob Roy Glacier. Guides are really best, because they know the native flora and fauna, and - they know the best trails and the best views! The Rob Roy track is fantastic, but I wouldn't take a rental car there - you need to ford 8 streams in the vehicle to get there *smile*. Thankfully, you won't be going in rainy season. 

4) Stewart Island. Everyone drives through the Catlin Coast for a day, and that's great. But spend 2 nights on Stewart, and you'll be amazed. Take a night tour to see kiwis on a beach, take hikes on Ulva Island, take hikes anywhere on Stewart! Like Doubtful, up above, it is off the beaten path - which makes it wonderful.

 5) Akaroa, on the banks Peninsula from Christchurch. Wonderfdul, friendly town, great views, sail cruise and/or kayak the harbour.

6) Otago Peninsula, at Dunedin. Great day hikes on your own. Plenty of nature tours if you want to see yellow-eyed penguins, etc.

 7) Wanaka - the town. Queenstown is more popular, Wanaka (imho) is nicer. It offers all the great things as Q'town, except bungy jumping: Jet boating, hiking, ski stuff, etc. The drive up to Glenorchy from Queenstown is a magical one, and be sure to stop for a drink in Glenorchy at the hotel before returning.The entire island is super friendly; but Wanaka and Akaroa win an award for being full of fantastically friendly folks *smile*. 

Others: Farewell Spit, if you like eco-tours and birds; Abel Tasman if you're an avid kayaker; Marlborough Sounds for hiking and boating. Blenheim is a must if you like wine, otherwise skip. Kaikoura has the whale watching, and beautiful views of the mountains.

 Hope this helps.

Posted Dec 24, 2010

I did a 4-month bicycle trip from Auckland to Queenstown.  Here were my fave destinations:

  - Welcome Flat hot springs, 8 hour hike through temperate rainforest (start not far from Fox Glacier on the south island)

  - Bicycle ride across Haas Pass to Wanaka.  Wow.

  - Coramandel Peninsula, North Island

  - East Cape, Maori culture

  - Swim with the dolphins at Kaikura

  - WWOOFing

  - Trek through Tongariro National Park (and a soak in a hot river)

  - Te Anu (far south island), Milford Sound, trek on the Dart or Routebourne tracks

Posted Dec 24, 2010

North Island - Black water rafting/ cave rappelling (abseiling). Auckland Museum for its vast South Pacific Collection. Sailing in the Bay of Islands. Hot sand beaches on Coromandel Peninsula. The geothermal areas around Rotorua. Naturalist camping if you like. Trout fishing (3-foot eastern brooks) in Taupo or fly fishing on south island if you fish. Any performing arts in Wellington  - youth hostel has a central location and open to all.

South Island - Kayaking in Golden Bay. Antarctic center in Christchurch. Puzzling World outside Wanaka. By late March Wanaka should be going golden with autumn leaves. Bungee jumping near there, too, as well as whitewater rafting. Franz Josef glacier on the west coast and the pancake rocks on the way down. Dunedin's whiskey and Cadbury factories, and the albatross reserve south of there. 

happy to answer any follow-ups as you plan.

Posted Dec 25, 2010

Hi Bill, we were just there this spring (South Island only). Check out www.activenewzealand.com. You've got plenty of time so I'd recommend choosing the places you want to see & taking it at your own pace rather than the tour, but their tours had some great highlights. I especially loved kayaking in the Marlborough Sounds. There are too many breathtaking hikes to list so just read up on what sounds interesting to you. I think you'll find Kaikoura looks a bit like the Marin Headlands, and the west coast more like Muir Woods!

Posted Dec 26, 2010

Just returned from South Island journey.  I was most surprised how much I liked my stopover at Mt. Cook National Park, particularly the Sir Edmund Hilary museum at the Herimtage.  If I could go back again, I would stay longer in the village and even give the mountain climbing, helicopter touring a go!  

Posted Dec 28, 2010

In the bay of islands I did 'The Rock' over night house boat trip.  It was so much fun.  Queenstown was one of my favorites.  If you rent a car the drive from queenstown up to the glaciers is amazing.  Give yourself lots of time so you can stop and look at the waterfalls and take the mini hikes that are marked off the road.  The coromandle peninsula is so beautiful. This is the place to do some kayaking.  I spent a month bopping around new zealand so if you have any more questions please ask, new zealand has been my favorite of all my travels!

Posted Dec 30, 2010

I went hang-gliding over Queenstown in the south island. It was amazing!

Posted Dec 31, 2010

the glow worm caves

Posted Jan 04, 2011

My wife and I did two weeks.  one week on the North Island starting Auckland, and one week on the South Island.  we drove both islands.  The north is home to hundreds of thousands of sheep, and you can really get actively involved in sheep shearing.  Also, the islands around Auckland are fun.  Also, be sure to ride the go carts down "rotorua" and buy the t-shirt that you survived it.

The south Island has the mountain ranges and also the milford sound.  Don't pass up doing a "hamilton"  ( q 360 degree turn) while you are at the fjords.  IN general, New Zealanders are fantastic people and just immersing yourself in culture is fun.

Posted Jan 04, 2011

I went to New Zealand with my family when I was thirteen years old. The trip was, as a whole, magical, in part because much of the scenery, especially on the South Island, feels otherworldly, with trees and plants that look just a few degrees off from the plants we're used to. The other incredible thing about New Zealand is the range of scenery within the islands' relatively small geographical  space. The two most magical experiences, for me, were:

Milford Sound - white dolphins speeding below the surface of the icy black water; huge, deeply forested fiords rising vertically from the water with clouds clinging to their sides... a dreamscape

Abel Tasman National Park - we stayed in Awaroa Lodge, an ecolodge unreachable save by foot or boat. A beautiful, sustainable place to stay on a peaceful and sunny stretch of the northern South Island coast.

Enjoy!!

[photo on road through Paradise, aptly named, near Glenorchy]

Posted Sep 14, 2011