Thanks for the input guys! So, it looks like the Remington 870 or Mossberg 500, 16" barrel, and buckshot is the winner. What about the amount of rounds these can take. I did a little reading and there was something about shorter barrels not being able to hold as many, but I'm not an enthusiast, so maybe they were talking about the barrel underneath? I just don't want to be forced to ask the burgler/rapist/murderer if they would be so kind as to rest a second while I reload.

And what about gauge? Is 16G enough, or should I go to 12G?
I agree with most people here: if anyone breaks into my home, I am not going to wait and see what their "intentions" are before I act (that sounds like your typical liberal-thinking TBH; can't "offend" the douchebag even though he is clearly at fault). I will give them one warning and one warning only (the tell-tale sound of a shotgun shell being chambered). After that, it's go time. As far as I'm concerned, any intruder gave up any of their "rights" once they violated mine. I didn't break into their house, they broke into mine. And yes, I will make sure only one or two shots are taken and are lethal; it's too chancy otherwise because they perp could be drugged up on something. Besides, 1 or 2 shots is probably all I'll have time for before things get tight.
As far as safety is concerned, the gun will be used if I have time to take it down from my hiding area and remove safety (gotta make sure the kids don't hurt themselves). But for more immediate defense, a nice aluminum baseball bat by the bedstand should suffice in a pinch.
Normally, I wouldn't go to these extremes, but it seems like there are more and more crimes nearer where I live. I'm sure part of that is due to increased desperation from the economy, but I bet a lot still has to do with the fact that criminals are almost given more rights than the victims in our great court of law.