Where in the US should I go?

[whoreable]

I am supposed to make raod trip with my parents to california to pick up my sister, but I will be flying back since they have free tickets that expire. Instead of flying straight back to Texas, I think I would like to go to some random place and walk around or rent a car for a day, check out some sights, sleep and the rental car or airport then fly home.

Where should I go?

This applies only to places southwest airlines fly.