I have a ton of shotguns, but my two go-to guns for home defense are my Remington 870 and Mossberg 500, both 12 gauge. It doesn't get anymore practical or reliable than that. I'm actually in the process of customizing the Mossberg for my wife. 18" barrel, synthetic furniture, and a 12" LOP stock are all in the works. Oh, and a VERY valuable tool that a lot of people overlook on a shotgun: a sling.