Briing a big pot of water to a boil. Add one tablespoon of sugar and one tablespoon of vinegar. Add the corn to the pot of water and bring to a roaring boil. Cover the pot, remove from the heat, and let the corn sit for ten minutes. Remove corn from the pot. When the corn is cool, cut the kernels off the cob, cutting close to the cob.Toss the corn in a medium pot with red onions, tomatoes, vinegar, olive oil, salt and pepper. Just before serving toss in the fresh basil. Add additional salt and pepper to taste, if desired. Serve cold or at room temperature.