Highlights

Even though my expectations were exorbitantly high, New Zealand's South Island did not disappoint. Although I have my favorite spots, I am quite glad that I went everywhere that I did go. Nelson Lakes, Mount Cook, and Wanaka were my favorite out of the set, and if I were to do it again, I'd try to skip as much of the drive down the west coast as possible.

Nelson Lakes

Nelson Lakes National Park - the Mount Robert circuit was beautiful, one of my favorite spots of the entire trip. Go up to the Bushline hut, you can probably stay there overnight if you have time for it (not sure how crowded it might be). This sunrise was 1000% worth it.

along the ridge, there's skiing in the winter!

Kaiteriteri/Abel Tasman

on the shore, almost ready to get to abel tasman

Split Apple Lodge - adorable place to stay, LOVED it. Definitely stay here if you can and if there's space.
Abel Tasman track - one of the Great Walks. I thought it could easily be done in 3 days, you travel between huts and stay overnight if you want. There are also water taxis to take you to different huts if you'd rather do a day tour. I kayaked around some of the islands, would highly recommend trying that. If you want to do a day hike, Anchorage has some short hikes, and the beach at Te Pukatea near Anchorage is supposedly one of the most beautiful beaches in the world. Stay in Anchorage Hut, Abel Tasman National Park 7183, New Zealand or Awaroa Hut, Abel Tasman National Park 7183, New Zealand

West Coast

Driving - meh. The general drive was okay, not amazing. I stopped in Hokitika for a bit, but while the sunset was nice, it was an average town. The views from Lake Matheson Walkway of the Fox Glacier are pretty stunning. There are some nice walks along there if you'd like to see them.

Queenstown/Wanaka

One of my favorite drives was the drive from Lake Matheson through Haast Pass to Lake Wanaka and on toward Te Anau (Milford Sound). You can see Lake Wanaka and Lake Hawea, both are stunning. You'll have lots of opportunities to pull over, and you should! In particular, The Neck is a nice place to go.

Ben Lomond Track in Otago near Queenstown - Great trek, the summit was gorgeous, and it doubles as a mountain biking spot. There is a great lookout called the Skyline Viewing Platform that you can stop at, or stop along the way to the summit.
Rātā in Te Nuku, Queenstown - Delicious, higher end restaurant. Treat yourself.
Bespoke Kitchen, Queenstown - Excellent breakfast/lunch spot, deliciously healthy
Roy's Peak Track in Glendhu Bay near Wanaka - Nice day hike just a quick drive outside of Wanaka, one of my favorites. Gorgeous and winding, perfect view of Wanaka almost the whole way up.

That Wanaka Tree in Wanaka - Because it's pretty cool to see, always crowded though. But the park around it is a nice spot for a picnic.

Kika in Wanaka - Delicious dinner, wish I'd had more than one night so I could have gone again
Big Fig in Wanaka - Like a way better Dig Inn, with bulk food that is actually well cooked.

Milford Sound

I did a day kayaking trip along the sound at Milford, and it was a nice kayaking visit. I think the cruise will be just as nice. After that, on the way back, I stopped by the Routeburn Track (another Great Walk) and did the Key Summit Track in Fiordland National Park. There are some really nice views and a nice little nature walk that takes you through some interesting vegetation at the summit.
Another Great Walk is the Kepler Trek. You can hire a boat from Te Anau, near the visitor's center, and cut out two hours of the trail. The hike up to the Luxmore Caves was lovely, and the Luxmore Hut in Fiordland National Park is well furnished.

Mount Cook

Sealy Tarns - nice viewpoint at the Aoraki/Mount Cook National Park Sealy Tarns Lookout, spot to rest, endpoint if you don't feel like going to Mueller Hut.

Mueller Hut in Mount Cook National Park - Super steep and strenuous. It was very hard to hike up, but the sunset from there was BALLER. If you're not into hiking that hard, don't do it. But if you pick one hard thing to do, this would be the thing I'd suggest.

Overall, the Mount Cook village was super cute, and the lobby displays nice, but nothing beats the views of Mount Cook at sunrise and sunset.