A long gun will generally trump a handgun for self-defense. If you're certain that you can stay barricaded with a single room and not have to assure safety of kids and other loved ones, the best place to be is behind cover farthest from likely entry portal. If you have to leave your room for any reason, a long gun becomes a liability.
For me, the best is a 1911A1. For others, it's what they shoot best and are most comfortable.