Seriously, guys. Assuming we aren't talking about a movie scene, a knife is way down on the list of effective home defense tools. If a firearm is not an acceptable option then probably a tazer or stun gun should be the next choice, although I think they are so anti-glamorous and un-rambo-ish that many guys dismiss them without giving it much thought. They offer distinct advantages over a knife (longer range, instant incapacitation, and most importantly, non-lethal). This last bit should be among the first things you consider. If you are willing to spend the time researching which knife will effectively dispatch an intruder, you should put at least a little thought and research into the legal implications of doing so.
Anyone with the stones to come into your home while you are there is probably packing a weapon against which your knife is going to be totally inadequate. If you are going to arm yourself against a real-world threat, do so with some common sense. Otherwise, you ARE a threat, if not to others, then to yourself.
