America West!
I only fly First Class and with them you can for the price you would pay for a full fare coach on most airlines. Their Frequent Flyer Program is the best and just won a huge industry award a few months ago. I get front of the line check-in and security and other perks. You can also burn their miles for flights on airlines like British Airways.
The service is generally pretty rock solid but they have hit some bumps as the are rapidly trying to expand and grow.
If you really want to know more about airlines this is the place.
www.flyertalk.com