Get a Judge or Governor. Great for close quarters, and not much chance of over-penetration.
Mossberg 500 or Remington 870
But get something with a butt stock on it, the pistol grip only models suck for accuracy.
I've been thinking about getting a Judge for those reasons.
Remington 870 or Mossberg 500/590 with my preference going to the 870.
And this...
The suggestions about the sound of racking a shotgun, or giving any real world recommendations for the Judge, sound like crap I hear from the jokers behind the counters of most gunshops.
Look at some Youtube videos of people shooting pistol-grip 12ga shotguns, or go run a few buck & slugs through one. You do not want one for HD. Hogue makes a great youth stock, and Knoxx makes a wonderful recoil-absorbing, length-adjustable stock, for the Rem. 870 or Mossy 500.
Check out, here, what Clint Smith, a well respected firearms instructor, has to say about HD with a shotgun. Do a lot more research on your own, but this isn't a bad place to start.
http://www.youtube.com/watch?v=-NSLxxDWpOI