You probably wont find great deals, but Southwest Airline is a good option.
Do you mean best airline to WORK for, or best airline to FLY? Some of America's top-rated are: SOUTHWEST CONTINENTAL AMERICAN DELTA UNITED JET BLUE
it depends on the airline. You should try getting an airline that doesnt require an adult to be with you under 18. I think Southwest airlines doesnt require anything but some sort of picture ID.