Finely dice tomatoes & onion and place in medium glass mixing bowl. Add chopped cilantro.
Slice jalapenos in half to remove the seeds and the membrane than that holds them. Finely dice peppers and add to tomatoes and onion. (Note: The membrane is where the heat of the pepper comes from. How much of the membrane you leave in the pepper will determine the heat of your salsa. You may want to wear gloves while you work with the jalapenos. If not, wash hands thoroughly with dish washing liquid afterwards and do not touch face.)
Add vinegar, garlic, chili powder and 2 tsp of salt and sugar. Toss well. Taste to determine if another tsp of salt and/or sugar is needed.
Squeeze lime over salsa. Toss once more. Cover and refrigerate or serve immediately with tortilla chips or with any Tex Mex dish.
As summer gets hotter and the tomatoes get sweeter, less sugar is required.Store in the refrigerator, covered, for 3-4 days.