When flying out of Cleveland, I am more likely to take Southwest than any other airline. They tend to have flight schedules that work for me, and the prices are usually lower than the other airlines, especially if I need to check a bag. Their gates also have plenty of seating. Even when the area is crowded, there usually aren't people sitting on the floor.
I think they did a better job of explaining their boarding process during my most recent trip than they did in the past. It can be confusing for new customers who are accustomed to having assigned seats, but I think they do a good job making sure people understand what to do and when to do it.
Make sure you ask for a paper airplane from your flight crew. They are super (cheap, light, flat) souvenirs for your kids!