Best:
Sydney (as everyoneseems to agree) - great food and wine selection, fantastic views, lots of space, internet, kids room, just super.
Honorable mention:
Nadi, Rarotonga and Papeete - love all three, good drinks and sandwiches (Nadi lags behind here, as the sandwiches only seem to come out for some flights, eg not for NAN-LAX) and great atmosphere.
Worst:
Well, LAX isn't great, but I don't find it terrible (drinks are good at least). What it needs is more space, more showers and definately some sandwiches and better snacks. Why, when Sydney has cake, cold cuts, sandwiches, salads and cheeses, LAX only gets Tasty Lees Pack-o Snacks? Surely you don't need a lounge upgrade to offer some sandwiches. But I'd say the worst lounge is the Red Carpet Club shared in London. Pretty terrible, good thing there are plently of other choices if you have *G (or a J/F boarding pass).
I also agree that the AKL lounge needs an upgrade. Also, the sandwiches aren't as nice as they used to be.
Why do I care so much about sandwiches?
Cheers, Zac