I think a lot of folks have missed the boat entirely here.
The question was one of an excellent home defense weapon. This poses some challenges, such as a weapon that can be used rapidly in close quarters and one what reduces the risk of wall penetration.
FIrst, nothing I know of that will stop a human being with any reliability will not pass through the wall of a residential building. Thus we are left with limiting any damage done after wall penetration.
The 12/20 gauge shotguns are certainly viable as defensive arms but are clumsy, especially if you need your off hand for a phone, flashlight or to urge children towards safety.
With the exception of small bore magnums, the use of a magnum round inside the home can only be justified if you live in a rural setting with no children.
The same can be said for the higher velocity autoloader rounds like the 9mm, 10mm, .357 Sig et all.
That narrows the field to some well-worn and "unexciting" calibers. .38 Special, .44 Special, .45 ACP, .45 Colt. We might even include the .380 ACP as the "floor" but I would be hesitant to call it even adequate to the task.
And before someone mentions it, I don't consider frangible ammo of any type or specialty ammo like Glaser and similar shot-load designs to be reliable for defense.
Apartment dwellers need to be cautious about which direction is "safe" to fire towards. In some cases, almost no direction can be considered safe (just that some may be less risky than others).
I live alone in a townhome. That means no common "living area" walls. Neighboring homes are within 3-5m of open space. So I use a .38 Special with +P ammo or a .45ACP revolver loaded with 255gr LSWC at 750 fps.
Let us also remember that the goal is to prevent any harm to the family members. It does us no good to "double tap" an intruder only to find that a miss has killed a child or house guest. Our goal is to stop or deter the intruder, not kill him. If the intruder dies as a result of his injuries, even if it's a case of I'm alive and he's dead and that's the way it should be. that is a byproduct of self-defense, not the ultimate goal