In a small bowl, mix warm water and sugar, then add the active dry yeast. Let sit for about 5 minutes, or until the mixture becomes foamy, indicating that the yeast is active.
In a large mixing bowl, combine the flour and salt. Pour in the yeast mixture and melted butter.Mix until a dough forms, then knead for about 8-10 minutes by hand (or 5-6 minutes if using a stand mixer) until the dough is smooth and elastic.
Place the dough in a greased bowl, cover it with a clean cloth, and let it rise in a warm place for about 1 hour, or until it has doubled in size.
After the dough has risen, punch it down to release the air. Transfer it to a lightly floured surface and shape it into a loaf. Place the loaf in a greased 9x5-inch loaf pan.
Cover the pan with a cloth and let it rise for another 30-40 minutes, or until the dough has risen about 1 inch above the top of the pan.
Preheat the oven to 350°F (175°C). Bake the bread for 30-35 minutes, or until golden brown. The bread should sound hollow when tapped on the bottom.
Remove the bread from the oven, brush the top with melted butter, and let it cool in the pan for 10 minutes. Then, transfer it to a wire rack to cool completely before slicing.