[deserth3]

If you don't want a gun you can always get a dog. A Belgian Malinois or Tervuren make great guard dogs (cops use them), love to play and are always ready to do something. They weight in at 50 lbs.
Mine is a mix but she scares everyone who comes to the door.
Downside; If you have kids get a puppy. Mine is a rescue and you can tell the child she was with was never taught how to treat a dog. Now I have to watch her like a hawk around little kids.

If you get a gun, I'd suggest a semi-automatic. When you're panicy and someone's breaking in the front door, it's a lot easier to insert a clip than put bullets in a revolver.