Researchers evaluated beaches, excursions, dining, adventure sports, and more to find the most activity-filled coastal escapes.Swimmers in the crystal-clear turquoise waters of Cala Goloritzé, Sardinia, Italy.Credit: Nick Brundle Photography/Getty ImagesWith so many beach-studded countries around the world, how does a beach lover pick the best one for a vacation? Especially if you want to park yourself there for several days and keep busy?Fortun…