In all practicality, home invasions are very rare. Most intruders come when people aren't home, as they are after your stuff, and not you anyway.
Now, if the rare sicko ever stumbled into my father's house, mercy be to the poor soul. I grew up shooting handguns, rifles, shotguns, full-auto machine guns (50 cal, 30 cal, BAR, etc). Although, he rarely, if ever kept anything loaded in the house. It's just not a good practice if you have kids. I would be willing to bet that you have a much higher probability of you or someone you love being hurt or killed by your own firearm than you are to ever be attacked by a home intruder. Of course, it might depend on where you live too
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However, the most practical home intruder deterent is none other than a good dog, as mtsgsd suggested. Criminals look for easy victims with easy opportunities. A dog makes noise, and if it's a big dog, it is a formidable opponent for any size man/woman.
As for my home though, I have neither firearms or dogs. But, like many people pointed out... many things can be weapons. I'm a very non-violent person... till I get mad. I'll pull a Grosse Pointe Blank if I have to and use the TV by my bed =) . haha