The museum Te Papa is one of the must visits when in Wellington. I loved the art display on 5th floor, but unfortunately photographing was not allowed there.
My favourite was an installation by artist John Reynolds - Clouds -
7081 white square canvases, 10cm x 10cm each, painted with a phrase or word from the Dictionary of New Zealand English. He used a silver oil paint marker, so when you move you can read some words but others are lost due to the silvery reflection of the text.