I voted 28 guage. Overall I enjoy shooting this guage the most for Skeet, followed by a .410. Now these are MY personal favorites for Skeet. When I shoot Trap, I always use a 12 guage, for Trap, the 12 guage is my favorite. When I go hunting Geese and Ducks I tend to favor 12 guage again in 3 inch persuasion.I guess I just can't narrow myself down to a single guage as all have their places in my shooting.
Beside, what is wrong with owning several different gauge shotguns?
Now, if you are going to nail me down to a single guage for all things, which is unfair anyways... I guess it would be a 12. It can do it all, it can do what any other smaller guage can do....I dunno, I still like shooting skeet with a mild 28 though.