I am awaiting an orientation at a local private gun club, so hopefully I will be able to narrow down my choice after that.
This is a good start. Try out as many as you can (if possible) and after a bit, you will notice not only which guns "feel" the best in your hands, "mount" the best, but also which shotguns have the most desireable feature-set given your needs. Again, for HD, the Mossberg 590A1 is my preference without a doubt. But, this does not mean its necessarily the "best" out there. Its just the best that I have come across, within a particular budget, in terms of meeting my particular need(s) (primarily HD, along with a bit of skeet/trap shooting, static target practice and the like).
The reason I mentioned a 12ga. pump is because, regardless of brand, it is a fairly straight-forward weapon in terms of its use, is quite forgiving and is certainly powerful enough and versatile enough (given the various 12 ga. loads available) for almost any use. Now, autoloaders are also an option. But, they can be a bit more finicky when it comes to ammo selection. In addition, the mechanism(s) they use can prove a bit daunting and/or frustrating to a newcomer (but, not to a huge degree perhaps).
Regardless of what you eventually end up with, once you enter the world of shotguns, Im sure you will find that one shotgun may not be nearly enough!
Keep us posted and enjoy the search....