First of all the term "home defense" is pretty broad. Let's say a person is qualified and wants a weapon to defend his family against the crazy who might come knocking on his door at 3 AM. A shotgun would be intimidating enough but it is unwieldy and hard to get to in an emergency. A handgun seems to be ideal for late night emergencies but I personally favor a wheel gun (revolver). You don't need to check a safety or feed a magazine or see if there is one in the chamber. The Tauris "judge" revolver is ideal. A revolver that can shoot a .45 or a 410 shotgun shell.
Well, I was going to address your question about which is the best HD firearm, but it's clear you're a revolver guy...which is cool. They're a fine choice. But which one...
Personally, I'm not a fan of the "Judge". For me, it would make a fine snake gun for horse riders out West, but if I was to choose a revolver for a home defense weapon, it would be this one:
Smith & Wesson 327 TRR8 Revolver - Article - POLICE Magazine
It's designed for HD and for the SWAT guy that first goes through the door holding the shield. A semi-auto in his hands would end up tossing empty cases into the guys behind him, and because he's holding the sidearm up against the side of the shield, that shield may impede the slide action of a semi-auto.
I like that it's designed to attach a light and/or laser under the barrel, while the top can take traditional sites or wide-view red 'dot' aiming systems designed for close quarters combat.
It's really cool HD revolver, IMO. I would choose .357 mag for the caliber.