A good read on Shotgun Home Defense Ammo. Their conclusion is that #1 buck is the best with respect to lethality without over penetration through walls and such.

http://www.firearmstactical.com/briefs10.htm

The Box O' Truth website also has some interesting discussions on various aspects of shotguns with buckshot - if different chokes work better than others, various brands etc. I read about 5 or 6 of his short articles last night and found them very informative.

http://www.theboxotruth.com/docs/theboxotruth.htm

Gunnery, gunnery, gunnery.
Hit the target, all else is twaddle!