If you have time to visit only one Tex-Mex border community, Del Rio is an excellent choice. It's big enough to offer a selection of appealing restaurants and culture, but small enough that its ambience is relaxed. It has an attractive downtown and historic neighborhoods and there's recreation aplenty at nearby Amistad National Recreation Area and Seminole Canyon State Park & Historic Site.
Laughlin Air Force Base, 6 miles east of town, is a major presence, as are growing numbers of winter Texans, who migrate to the area from November to March for the mild weather. Also, watch out for sudden and severe thunderstorms – moody, yes, but also the reason there are so many hail-damage repair places.