What guns do you have in your house?

[OVERKILL]

 In my opinion, you can't go wrong with a 500. Extra barrels are available in a pretty good assortment (even a 50 caliber muzzleloader conversion) and at decent prices. For a pure defense shotgun one of the 8 shot models would be good, I like the way they look. Being raised on lever actions the full length tubular magazine underneath the barrel just looks "right". The only downside to them is that almost all the accessory barrels are for the 5 shot model.