Flygon and Vibrava should get Quiver Dance. It would be viable and not broken, and give it a niche as a special boosting Dragon-type and/or a special boost Ground-type. It gets Boomburst, Earth Power, Dragon Pulse and Draco Meteor, Bug Buzz, Fire Blast, Flamethrower and Giga Drain, not to mention Hidden Power, so it has plenty to work with on the Special side. And its stats - 80/100/80/80/80/100 - mean it would be decent, but not overpowered. It could even run Physical coverage if need be. Quiver Dance would set Flygon apart and make it viable, if niche. It wouldn't be hard to get, either - just an egg move from some of it Bug buddies.

Quivgon when?