Shotgun with #6 shot maybe #4 shot, reason is that it will not penetrate two layers of dry wall. Then 38/357 with wad cutters for same reason. With others or chance of others in home it's not a good idea to over do it.
For home defense I would start out with what is closest or available to me at the time. A .40, a nine, an 1100, 7.62, and if all else fails, club 'em with Grandpa's s/s 12 ga.
Ruger LCR in 38spl (also my carry gun) with laser grip, but if I can get to it my Rock River TAC CAR loaded in Hornady Critical Defense .223 with Eotech sight.