The Northern Territory is way at the top of my favourites states in Australia. I spent a long time in and around the Alice Springs area, volunteering in national parks in the area, swimming in waterholes and hiking around gorges. It's a stunning area and feels like home whenever I return.
My favourite regions are Rainbow Valley, just south of Alice Springs, and Trephina Gorge to Alice's East. The gorges and scenery are out of this world. Further north in Kakadu, I had a lot of fun four wheel driving to remote spots such as Twin and Jim Jim Falls, where it's hard not to see a whole day pass taking photos of the falls, swimming and looking out for crocs!