If you value your time, AA and UA are the only nonstop options. UA has been using a 747 on that route recently, which I try my best to avoid. AA is still flying 772s (might switch to 77W next year with skinnier seats), which are decent enough.
You can often save money by connecting in Japan, Korea, or even Beijing if you're cool with Hainan Airlines.
CX is one of my favorite airlines, but HK is a substantial detour (i.e. not worth tacking on unless you make it a stopover).