I liked Oklahoma. The drive is lovely (where the wind come whistling down the plains.) It is pretty laid back and certainly affordable.
It is known as the native state as there are quite a lot of reservations. I definitely think that is what you should spend your time doing in this state. The fantastic Chickasaw Cultural centre is a great way to spend the day. Seriously, I would eat there every day if I could.
Visiting Oklahoma is a great opportunity to learn more about the original inhabitants of the country. It is definitely worth a visit and would be an enjoyable day for everyone.