Many visitors to New Zealand eventually find themselves driving between Dunedin and Christchurch, and a good proportion of them see the route as something to undertake in a single day following SH1 the entire way. This is a real shame, as this is one route that truly rewards a slower approach--and there is a far better route!
Assuming you start in Dunedin, you head north out of town along SH1 along some beautiful coastal scenery and before long you will be in Waitati, where you have a great opportunity to visit the Orokonui Ecosanctuary, the South Island's largest sanctuary for local flora and fauna. This is a must-see for any wildlife enthusiast, or anyone who is interested in seeing some truly spectacular natural scenery.
Further along, you will drive through more beautiful coastal scenery and soon you will reach the coastal fishing village of Moeraki, home to the famous Moeraki Boulders, which are another must-see. If you time your visit right (i.e., if you are here around an hour before dusk) you also can enjoy a viewing of the world's rarest penguins, the Yellow-Eyed Penguin, along with other marine creatures, at the Moeraki lighthouse. You can also dine at Fleur's Place, one of New Zealand's most acclaimed restaurants.
From Moeraki, you head further north to Oamaru, one of New Zealand's most charming and best-preserved towns, with an impressively maintained historic centre boasting an incredible number of stunningly ornate colonial buildings. A walk along Harbour and Tyne Streets, and Thames Street, is unlike anything else in New Zealand, with countless shops, cafés and museums to stop in and visit. Oamaru is also New Zealand's capital of Steampunk, an art genre that uses Victorian-era technology to create futuristic doo-dads and gizmos. You have to see it to believe it. Oamaru is also home to New Zealand's largest colony of Blue Penguins, the world's smallest, who come back to their land-based nests every evening at nightfall, which you can watch from the comfort of the Oamaru Blue Penguin Colony.
As you continue north from Oamaru, stop for a bite at Riverstone Kitchen, one of New Zealand's winningest restaurants, having won two Cuisine restaurant awards, in 2010 and 2011, after you stop for a photo in Hilderthorpe of the 45th Parallel marker, noting the point where you are equidistant from the South Pole and the equator.
After driving through Timaru and Temuka, you will come to the town of Winchester, where you will divert from SH1 onto the "Inland Scenic Route" (SH73) for a far more scenic route to Christchurch. As you turn off this road, you will almost immediately be struck by the incredible sight of the beautiful mountains of the Southern Alps looming ahead of you. Shortly after the turnoff you'll reach the town of Geraldine, with a number of interesting shops and restaurants, and as you continue along SH73 the scenery just gets more and more beautiful. There are numerous turnoffs you can take to see waterfalls, gorges and other sights.
SH73 will take you into the western suburbs of Christchurch, close to the airport, perfect for catching your flight home (or, if you start in Christchurch, just reverse the above itinerary). It's a drive you won't soon forget!