I regularly fly Southwest Airlines when it is an option. They usually have either the lowest fare or a very competitive one. In my experience they have better on time departure and arrival than other airlines. Some people prefer assigned seating but that really doesn't bother me. Their whole organization makes things fun and this can definitely be seen with their flight attendants. Check out this creative safety announcement. If only they had flights from Kansas City to Atlanta, I'd be sure to put them at the top of the list.