NightFire

I also prefer a shotgun for home defense, I use a pistol for concealed carry.

CalHunter

One that you are able to shoot well, can find and operate safely in the middle of the night when it's dark and can prevent any kids or other people in your house from accessing and using unsafely. Everybody (me included) has the weapon we prefer and are willing to bet our lives on in a self defense situation. You are the only one who can accurately determine which gun works best for you.

FWIW, I personally prefer a Glock .40 caliber pistol because it's what I've carried as a duty pistol for the last 17 years. You might prefer a revolver. Whichever gun you choose should be one that you can safely and effectively defend yourself with and still find a means to prevent any kids in the house from getting access to it.

Although different states might have different laws about when you can and can't use deadly force (like shooting your gun at another person), in most states you are allowed to defend your life or another's life from imminent threat of death or serious bodily harm. Normally that means a person who is going to assault you with some kind of weapon and you are likely to get killed or seriously injured if you don't use your firearm to shoot them.

LE does train to shoot center mass (in the chest) unless center mass hits aren't stopping the threat or the person is obviously wearing body armor that would stop your firearm caliber. In that case, LE teaches cops to switch to a head shot(s) to stop the threat.

Just about any reputable police academy and any creditable Law Enforcement training is going to train cops to shoot to stop the threat of imminent death or serious bodily harm. Once that threat has been stopped, you don't continue to shoot the person.

The idea that shooting a person till they die (as opposed to stopping when they are no longer a threat) will somehow prevent a lawsuit completely ignores the fact that any family members of that suspect will likely file a lawsuit if they can prove you continued shooting the person after they were no longer a threat. Just about any time you shoot another person (whether they live or die), you can rest assured that some LE agancy, District Attorney or Grand Jury is going to have to conduct an investigation and determine if your shooting was legal and/or justified.

Hope this helps some. Good luck in your decision and be safe.