Plain and simple for me:
6 family size teabags
2 cups sugar in a gallon jug
Fill a 2-quart saucepan with water and bring the teabags to a boil with the teabags in the saucepan right off the bat. Maybe I'm lazy, but I find that the tea tastes better that way rather than putting the teabags in after the water starts boiling.
After the tea comes to a boil, let it steep for about 5 minutes. Pour it into the gallon jug, and stir it up. Add ice, which should melt fairly quickly in the hot water, and water to fill. If you want you can add a couple splashes of lemon juice as well.