My father only owned two guns...an Ithaca 12 gauge model 37 and a Remington 22 pump model 12. He could have bought other guns, but felt no desire to do so. He never owned a hand gun, saw no need for them. He said that you could hunt anything in our state (Indiana) with them. The shotgun for upland game, deer, waterfowl and home defense - BTW he never locked the doors, he said all you do is keep your friends out. The 22 for anything else you might want to shoot or hunt (like squirrels or vermin). He even used the 22 for putting down farm animals for butcher including hogs and cattle. Even though the laws have changed since then, you could still hunt anything in these parts with those two guns. If I were to only have one gun, it would be a well made 12 gauge pump, either a model 37 or model 870. Of course that would be no fun at all, I like choices and variety.
Good Luck and Good Shooting