My PERSONAL OPTION for home defense is a carbine variant rifle, but I still think that your pistol should be your primary means of defense in your home.
1) Deploy handgun and engage threat
2) Under your own cover fire or if opportunity presents itself, use your handgun to maneuver yourself to wherever your bigger guns, more ammo, vest(s), phone(s), etc are located
3) Once properly armed or if opportunity does not present itself, either fight or retreat
4) If you decide to continue to fight, follow steps in my signature line