the reason id be 'biased' towards an 870 is that if there is ever anything you need for it, the EE is full of hundreds of posts of 870 items. barrels, stocks, replacement parts, etc. if you buy an 870 and decide you want, say, a turkey barrel, a home defense barrel, a rifled cantilever barrel, a synthetic stock, etc then youll easily find one in the EE.
not so with most other models. some have practically no used aftermarket. oh, and good luck buying a second barrel for that Benelli Nova - you may as well just buy a second Nova (in comparison you can pick up most 870 barrels for under $150 on the EE).
i am not saying that the other recommendations arent good guns - just that if you are a total newbie to shotguns and arent quite sure what you want (as evidenced by this thread), then you could do worse than buying an 870. if you screw something up and get the wrong configuration, or later on decide you want to use the shotgun for something else (turkey, waterfowl, whatever) its really no big deal as you can very quickly and easily swap parts on the EE.