"Lonely Planet" or "Let's go" best for NZ?

I'll be needing a guidebook of some sort when travelling around here
in New Zealand, but which one?

Everybody else has Lonely planet, and in Australia I bought "Let's go
Australia" to have something different.

Which one is best?

I plan to travel around in the less touristy way if it doesn't prove
to be too hard. I'm not really a person who joins organized tours and
the like, and would need a book that gives more "local" information if
possible (i.e. local buses as opposed to guided tourist buses to get
to places).


Hallvard