A handgun wouldn't be my first choice. But that's just me. I'd much rather have the extra stopping power you get with a long gun. My home defence weapon is a Tavor, set up with a Aimpoint Pro, Surefire light, and a single point sling. It's short, maneuverable, low recoil, and it can be shot very easily one handed. Plus, it's the gun I shoot best, and my wife is comfortable shooting it.
I also keep a 870 in the bedroom safe, just incase if I need to arm my wife, I can pass her the Tavor, and I can use the shotty.
I realize that it's highly unlikely that somebody would break into our home looking to do our family harm. But it's also unlikely that out house will ever burn down. But we still have a fire alarm and extinguisher in the highly unlikely case it ever dose.