I agree with Airforce (see above) with the notion of "racking" a shotgun. That F#*cker will know I have a gun when it goes BOOM.
As for which shotgun, as its already been stated, its almost a matter of personal preference. For HD, I'd stay away from the the Stoeger mostly cause I know nothing of its reliability. Rem 870 of the Moss 500/590 is the direction I's take it. Go to a reputable gun dealer with a large selection of shotguns, and start puttin' 'em up to your shoulder, flick the safety, work the action, and then decide which is for you.
I currently only own one shotgun of my own. It is a Moss 500 "Tactical Turkey". Mossy Oak finish, 6 position adjustable stock, fiber optic rifle sights, and the receiver is drilled and tapped for optics. It came with a XX Full turkey choke, so I had to drop a few bucks for a larger choke to pass slugs. Its primary duty is Turkey, but with the addition of the larger choke, it will now pull double duty as a HD Shotty. For $400, I'm happy with it, although I am now thinking I should have gotten the 835 Ulti-Mag (chambered for 3 1/2 shells)
I do love the 870's though. I was bummed when we switched shotguns in the navy. The 870 just felt a little more "substantial". I share the same feeling with the switch from the M14 to M16's/M4's on ships. I'm not knocking them, but when you heft up the M14, it just feels "meaner".