I have lived in the US, Canada, UK, Germany, and France, and I prefer New Zealand to all of them by far, for these reasons:
As opposed to the US:
Free healthcare
A great social security system
Four weeks minimum paid holidays a year
No guns
Very low crime
No capital punishment or other, embarrassing anachronisms
No snakes
As opposed to Canada:
Mild climate
Green winters
Compact; you can be anywhere over the weekend
No bears or wolves
As opposed to the UK:
Uncrowded
No class system
Low house prices
Restaurants cheap and good, lots of them, too
No postcode vanity
As opposed to France:
Tough call - NZ is actually a lot like France in many ways; if you're French, might as well stay home, not much difference. Possibly more seals and penguins here though.
As opposed to Germany:
Kiwis are easy-going, and get-togethers are relaxing
None of the weird laws of Germany exist here
No army conscription
Low taxes
No cold winters
No road salt
Top speed on highways is 100 km/h
General pros and Cons:
Pro:
You won't find another country in the world which happens to be as friendly, beautiful, relaxed, safe, free of creepy-crawlies, socially responsible, and open-minded as NZ.
Cons:
Wages could be higher
People drive like mad
Heating is a shambles in most houses
NZ red wines only now beginning to be drinkable (I still prefer Aussie wines).
;-)