While my daughter still can be dragged along, we are on the "See the USA" summer series.
The last few years we have done South Dakota, Wyoming, Montana,Florida, South Carolina and parts of Colorado and Arizona.
I voted for the Upper Peninsula of Michigan this year but was outvoted for either Arizona or New Mexico.
Las Cruces is a cool spot for a quickie. It's a college town. See the Organ Mtns. Then go to Trinity test site, but wear a radioactive-repellent suit! I bet all the cool spots are in the northern half of the state, though. Like Taos and Santa Fe... But those wide open spaces are pretty cool.
Kristen, you go yet? You're really doing this over the UP? UP MUCH prettier, but then again, I live in the desert setting. I was going to throw in a plug for Albuquerque by UNM - cool little main drag and friendly (and odd people). We just did a trip there and enjoyed the NM landscape in general.