Domestic I will always fly Air New Zealand. If that isn't possible or is too expensive then I just won't fly. A shocking experience on Jet Star means they will never get my custom again.
I don't generally fly international much anymore but my wife does - and her preference is always Singapore - mostly because of Changi. If that isn't possible then Air NZ via Hong Kong. And if that isn't available then anyone else. Singapore probably worth a 20% premium before we think about others - Air NZ via Hong Kong a 10%.
Got a family trip coming up next year to Orlando and are thinking about flight options at the moment. Air NZ coming in quite pricey and with long US segment on a US carrier (United I think). We are therefore reasonably tempted to go Qantas and fly the wrong way for 3 hours to Sydney, back over the top of NZ to Dallas and then have a shorter US leg on AA. Its an extra 6 hours total flying time but saves us a little money and means we avoid spending as long on a US carrier as we would with the more direct route.