Well, everything depends where you are flying from, and where to. From my experience, jetBlue is the best airline, with very cheap fares. Though they do not serve MEALS on board, they do serve snacks, have TV's in every seat with DirecTV, and XM Satellite Radio and free movies, depending on where you're flying to. They have some of the most experienced pilots around, that fly a very new fleet of airplanes, and take very good care of the passengers. Other cheap, but less friendly airlines are Delta, and by far the worst service, American airlines.
It depends on where you want to fly. It really depends on the destination and hub airports of the major airlines.