Flying as frequently as I do from Australia to the US you learn a few things.  Here’s my current tips and tricks:

1. Qantas is by far the best airline on the route with stunning lounges, the best Inflight service, great seats, and friendly staff. But…
2. They are ridiculously over priced. Both United and Air NZ offer great value for money with a reasonable drop in service in United’s case and close to parity with Air NZ.
3. Don’t fly Qantas to San Francisco. They have their museum grade, ancient 747-400s on this route. The seats are awful and lie about as flat as a Byron Bay Backroad. On my last three flights neither the power or lousy video screen worked.  On the LAX route you get fancy new planes. Don’t pay the same for less.
4. United is flying the Dreamliner to San Fran and LA. It’s fantastic.  There is something about the lighting and air quality that makes the flight better.  But alas, it’s United so the food is awful, the staff unpleasant and any other hope of little touches are best not anticipated.  
5. Air NZ via Auckland is a great alternative if the price is right.  Great staff, generally modern planes on the long haul routes, and upgraded lounges that as a whole are far too packed with travellers from a multitude of airlines to enjoy.
6. American is flying these routes more. But then you’d have to be seduced by an amazing price or really want to fly American. 
7. If heading to NYC, try the Sydney – Honolulu – NYC route. It’s an overnight flight so sleep is easy and you have the option of a day or two in Hawaii on the way up or back.

Hope this is useful and welcome other thoughts and tips.