For the sweetest corn possible, keep just-bought ears at room temperature; refrigeration causes the natural sugars to convert more quickly to starch.
Fill a large stockpot with cold water. Set over high heat, and bring to a boil. Add sugar. Add corn, and let simmer until just tender, 3 to 5 minutes. Remove from water with tongs. Serve immediately with herbed butter, and sprinkle with salt and freshly ground pepper.