Hi Lou,
As said above, it's horses for courses really, but here's my take:
Auckland - good for jobs, highest pays around but biggest, most expensive city to live in and high crime, small houses for a LOT of money! Only worth considering if you want big city life, cos in that aspect Auckland is great and has the most to offer of any NZ city.
Hamilton - You've seen for yourself so don't need to explain, but living here could depend on how long you can hold out for a job. Hamilton's more of a word-of-mouth job market so whats advertised isn't anywhere near whats available usually. It's also a slower pace of life so not everything happens as quickly as you'd like some times. Housing is cheaper than the other majors, but this is because it's not on a beach and isnt a touristy area, which is why most people don't look at the place, and why kiwis who don't live in Ham say it's rubbish. More of a functional city than a lifestyle choice, being mainly a dairy farming area.
Wellington - Seems a fairly balanced place, good jobs etc, only downsides seem to be commutes, limited spacious housing unless you extend your commute considerably and any minute now they expect 'The Big One' to hit (major earthquake) which should see most of the city slide in to the sea. (Thats the reason why WG wont entertain moving there
) I think the wind is over-hyped a lot, but it does get mighty windy there on times.
ChCh - Well, thats on the South Island!! Who'd want to live there?! I don't know if it's unbalanced media coverage but seems to have a disproportionate amount of crime for the size of the city, and the most reported problems with boy racers etc. I guess it's because ChCh is isolated in many respects, it's the only major city until you hit Dunedin so the kids are probably bored. As I say though, this could be just down to media coverage. Get this too, no word of a lie I've also heard many a kiwi call the locals - wait for it - worse than Aucklanders! Apparently Christchurchians are becoming elitist in their attidute and have the worst racist outlook!! But, shouldn't believe everything we're told.
It's the most popular destination for Brits though, so it must hold something and it certainly does offer a good amount of jobs and reasonably priced housing!