I vote for the reliable Rem. 870 in 12 Ga., 26 -28" barrel. With the interchangeable screw-in choke tubes, it is versatile - and (as I recall) lighter than my autoloader (11-87 Special Purpose).
In the event that you're likely to begin hunting waterfowl, get a minimum 3" chamber. I am uninformed if Remingtons have made the change to 3 1/2", but Mossburg has, I know.
In years to come, you can always go to a Benelli 3 1/2" auto...