I will avoid the smart-alecky response and seriously ask, what are you hunting? Just as you need the proper tool for the task at hand, the proper gun depends on what you are hunting. You probably wouldn't want a .12 gauge to hunt rabbits and squirrels. If you are hunting deer in a state that doesn't allow hunting with rifles then you probably would want a .12 gauge loaded with slugs.
What is .12 gauge..?