If you can get into them, then try to get into UMelb and ANU for physics. They're much better at physics than UNSW and USyd, and that shows in the international rankings. I also hear that UMelb only ranks well because it follows the international system and the social life is shit, but maybe you can ignore that if having the 14th best physics department in the world is a good enough prospect.
In short, I'd put it as UMelb = ANU > UNSW > USyd.