Wow- thanks everyone for the great suggestions. As for my interests- more about nature and scenics as opposed to cities, but I'm not averse to almost anything especially if it's unique / worth seeing in NZ. Culture? Yes Scenery? Definitely Hiking? Yes if something unique to see Wineries? No Adventure? Not much. I'm quite open to driving and/or flying if that means for example, skipping to the other side and seeing more things. I've never tried astro-photography so that sounds exciting! I'm not clear if 3 weeks is enough time to see both south and north islands (some folks told me 2 weeks each is suggested a minimum).