Single Time swing is a great thing to teach. It doesn't take much coordination to pick up the basic steps and timing.
Kids also really like the Tango...It's easy to teach and easy to learn at a basic level. They like the whole Addam's Family component. It's featured in the movies a lot and they all love to do the Promenade's...
I've taught both to kids 6th-12th grade and they liked these dances better than any others.
Also...don't forget Salsa...kids dig that.