Cut down version of Hundertwasser flag (no black bar at the front). I like it because it covers the clean-and-greenness aspect of our international reputation and because it emphasizes both our unique endemic flora and the uniquely Maori element in our country-wide culture. It's not bombastic or chest-beatingly nationalistic (as anything red white and blue is -- at least to me). It's upbeat (literally -- the koru curves upwards). No other country's flag is even vaguely similar, so it's distinctive. And it's just plain attractive to look at.
I especially DON'T want the All Black flag, which looks to me (and potentially everyone outside this country) like a white feather (indicating cowardice) on a black ground (suggesting ISIS).