Low Recoil #4 Buck is what mine is loaded with as I find it more appropriate to use indoors. Full power #4, 00 or 000 buck will really shred a wall and kill thing beyond my target.
I really don't use (or want to use) any long gun for home defense! I have a Colt Double Eagle within reach when abed. It carries 8 rounds in the Magazine - and I have a second mag by the gun. A handgun is far easier to maneuver in a home, if I can't hit a BG every time I fire, as short as the distance would be in my home, I had better use it as a club! Guess I could set my M1 Carbine, AK, LR 308, Garand or one of my shotguns by the bed but I think I will stay with my handguns.
I can't think of how anything beats buckshot for a HD shotgun. I have been testing with the PMC Low Recoil 00 Buck and like it. Patterns a little looser than regular Federal 00 buck in my KSG but I don't see that as a bad thing at the short ranges I would have to use this in my home.