jwong, I think you'll want to use shot for home defense, according to everything I've been taught. Slugs will penetrate like crazy for one thing. They're great for just that - penetration against a fairly hard target. And, for distance shots - in our tactical shotgun class we we taking 50, 75 and even 100 yard shots with slugs.
However, shot gives you a good pattern at medium range, and a large hole at very short range (you still have to aim - it isn't a 'scattergun' at short range, as some think). Seems like most folks use #00 buck, and there is also a low-recoil #00 buck as well. Some argue that #1 buck is an even better choice because the shot is nearly as large, but there is a greater number of pellets - see
http://www.firearmstactical.com/briefs10.htm . I've also seen recommendations for #4 buck, as well as using a couple of rounds of bird shot as the first out of the tube.
Based upon everything I've read, seen here on TFL and been taught in class, I decided on 2 rounds of #6 birdshot (first to load - I've got a couple of kids, so I'm pretty sensitive to the penetration issue), then 4 rounds of #00 buck. I have 3 more rounds of #00 on the sidesaddle, along with 3 slugs. I'd like to try the #1 buck, but it is a real pain to find. I've tried to special order it, but my supplier doesn't seem very motivated.
If you haven't done it yet, try to take a Tactical Shotgun course. Helps a lot with technique, and you get to pepper them with questions.
Take care. Regards from AZ
[This message has been edited by Jeff Thomas (edited September 04, 1999).]