My recommendation is to avoid anything that doesn't have a proper buttstock. Those pistol grip shotgun rigs might look fearsome and handy to transport, but they are slower to put on target and forward heavy enough to make you shoot way too low in a panic. Also, with no buttstock to use as leverage and brace against your body, they can be easily redirected or taken from you by your opponent in close quarters.
I have my favorites, too. Like some of the previous fellows, I prefer the recoil-operated humpback Browning design in an auto - Remington, Savage, FN. They are all reliable.
2nd behind the semi-auto would be the Winchester M-12 pump. They hold 6-shots when fully loaded and aren't too barrel-heavy at that. I've seen several nice M-12s come through my local Cabela's with riot-length barrels and priced at ~$200 because of the abbreviated barrels. I hesitated each time for a day or so, and when I went back they were gone.
For home defense, I prefer a wooden buttstock - not because of aesthetics, but for the extra weight. At home, you are not likely to be carrying it for extended periods, and the extra weight will go a long way toward mollifying recoil and help you to get off more precise subsequent shots.
Photos and video clips I've seen of the Posse Comatatus brigades running around in the woods around here indicate that they prefer the black fiberglass and the pistol grips. :lol: