Where is best to study in New Zealand?

I currently live in Norfolk (UK), and am probably gonna end up studying Environmental Geophysics at the UEA (not for certain yet). The course includes a year in Australasia, and it has been my dream to see NZ. I have heard that South Island is better than the North (in terms of scenery + geographical features to suit my course). Have particularly heard good things about Christchurch and Dunedin and thier Unis. Is this true? Does anybody else have any other recommendations as to where to study in the country (North or South Islands)?