What I most loved about Te Papa is the educational and interactive way it introduced me the history of New Zealand. in my eyes, any museum can do well just by beautifully displaying outstanding art work but a national museum must stand out by how it represents its country. Worth having a look at the videos on how human rights evolved in NZ and how the islands were populated.
Te Papa is a must see while in Wellington. Unless there is a special exhibition which attracts a fee you don't need to pay at all to see the exhibitions.