As noted, we don't know what your interests are or when you are visiting. In west Texas there's Big Bend and the Davis Mountains. Quite pretty, but you're driving across the widest part of TX to get there. A place to visit in spring or fall. The hill country is nice in spring when the wild flowers are blooming. The coastal areas are nice is spring and early summer.
I would wholeheartedly agree with a couple of the previous posters and also advise you to consider Arkansas, esp. the NW part of the state. A wide variety of outdoor activities.