What countries have a plural executive?
I guess you could make the argument that the United States has a plural executive because of the power of the Cabinet, but I was hoping for something more apparent.
Switzerland has a seven-member collegial Federal Council. After the death of Tito, the former Yugoslavia set up a collective presidency (of course, that particular institution has now gone the way of the Hapsburgs). The highest authority in the United Arab Emirates is the Supreme Council of Rulers, made up of the seven emirs of the constituent states of the U.A.E. They do, however, elect a union president and vice president from among their membership, who serve five year terms, with the president appointing a prime minister and other ministers to do the actual day-to-day running of the country, so this probably doesn’t quite quality. In general, modern plural executives seem associated with confederations with weak central governments. Of course, the ancient Roman Republic had two consuls who equally shared supreme executive authority, especially in foreign affairs.
I’m not sure it would be categorised as executive but whilst Fiji has a parliamentary democracy (at least between coups anyway), ultimate authority would be considered to be vested in The Great Council of Chiefs.