There are many choices for sweeteners out there these days. My favorite sweetener is erythritol in both powdered and granular forms.
I also use Fiberfit along with the erythritol to balance out the cool flavor. I like Fiberfit because it has 0 carbs and contains soluble fiber.
If you don’t have (or want to use) Fiberfit, you can use another liquid sucralose, increase the amount of (or use) erythritol, or sub a sweetener of your choice. 1 teaspoon of Fiberfit = about 8 teaspoons of sugar, so make sure you use the appropriate amount of your sweetener of choice. You may also want to experiment to get the sweetness you want, since my preference may be different than yours.
I get Fiberfit Liquid from Netrition. A large bottle lasts a very long time.
I also get Sensato Erythritol from Netrition. It comes in granular and powdered forms.