On the world stage? Everyone should be voting US on that poll considering that the majority of international organizations out there (and indeed the international system itself) were built by the United States, who remains the largest contributor to them.
US has the largest GDP, strongest military, and is consistently one of the most sought-after sites of investment.
I'm going to say Germany. Despite an aversion to any real military activities, they are the only country on there without a deal-breaking issue of some kind.
Japan, specifically, is hopelessly right-wing and revisionist.