For absolutely the most versatility, a smoothbore 20" bbl with choke tubes is the ticket. One can adjust the pattern to any load and range.
The 20" bbls I've seen mostly have rifle sights, great for slugs, good for HD and CD, not so great for shooting flying stuff. A 21" turkey bbl will do less well for slugs, better for wingshooting and about the same for the "Serious" stuff.