Buying used it don't matter what brand is on the car. The previous owner(s) and how they took care of it is what's going to decide the longevity of that vehicle. You're taking a gamble regardless with a used vehicle. Damn what the dealer and carfax says.
Don't just go off the brand name, check that shit thoroughly. Go for the one with the least amount of miles. Test drive checking for any noises and vibrations that seem irregular. Pop the hood and listen to the motor. You need to hear a consistent purr of the engine. No strange knocking, hissing, or tinks. Check belts for chaffing, cracks, or any signs of being worn. Make sure there are no leaks, no smoke, no wet area's around the motor. check all reservoirs, although any dealership worth a damn would have that covered at least, still check it. Make sure all your dash instruments work. All the buttons work. Lights. turn signals. Maintenance cost. Warranty. Gas mileage. Yada, yada, yada...
Most mechanics I've met would recommend a Ford.. Toyota's are good as well. But far as chevy vs dodge goes, chevy has been slightly ahead of that curve.