I always carry a snub-nosed .38 in my pocket loaded with +p Federal Nyclad hollow points.
When weather permits, I carry a S&W 625 revolver in .45 acp.
Images are not to scale, trust me the .45 is bigger than the .38
Both are utterly, absolutely reliable. If I thought I might have an encounter with a pissed off meth head, I might feel the .38 was not enough gun. But then, if I knew I was going to a gunfight, I'd take the shotgun.
Home defense? Shotgun loaded with 00 buck. A Remington 870 or Mossberg 590 with a Surefire fore-end will do the job nicely. Then buy yourself a Second chance vest. Keep the pockets loaded with reloads, a light, a handgun and a cell phone. Keep the straps open on one side so you can slip it on quickly and stash it under the bed. As previously noted by another poster, have a plan and safe room and make sure your family knows the plan.
Go to a range and rent them all. Once you decide on armament be sure to get some training. FWIW, I recently took a tactical shotgun class, I was amazed how little I knew and how wrongheaded I was with what I thought I knew.