I'll start this reply by saying that for a great reliable shotgun that you can use for everything from deer to turkey to quail to rabbits and squirrels the 870 gets my vote 100% of the time. That being said its not my favorite bird gun. I own several other shotguns and the 870 ranks about 2nd to last. My favorite is a three way tie which is depending on what I'm hunting. They are:

28ga Ruger Red Label o/u
20ga Browning citori o/u
12ga Browning Citori o/u

After that it would be either the Ducks Unlimited edition 1100 12 ga or my Spartan 12 ga.

Then either my winchester pump 20ga or 870 express.

Just my opinion, but I like a light gun if I'm gonna be spending the day walkin in feild and quick follow up can sometimes be incredibly handy and the 870 gets beat in both catagories even though it is probably one of my all time favorite guns and will never leave my arsenal.