If you're planning on crossing into Mexico, the crossings at Juarez reached via El Paso or Santa Teresa are far busier than the one near Columbus, with all that that entails -- longer lines on the US side, but more to do once you're over the border. The mercado is busy, schlocky, and colorful. One warning: drinking age in Juarez is 18, and on weekends, many younger students at New Mexico State University in Las Cruces, and at colleges in El Paso, make the pilgrimage to indulge. Traffic back into Las Cruces can be frightening at such times. Be cautious.
Some destinations in other states that are close to their borders with New Mexico and hence reachable as day excursions are clockwise from the southwest corner: