Process first 6 ingredients in a blender until smooth. Gradually add ice, processing until smooth.
Rub lime wedges over rims of stemmed glasses. Place salt in a saucer; spin rim of each glass in salt. Pour margaritas into glasses, and serve immediately. Garnish, if desired.
Note: Margaritas may be made ahead and frozen. Let stand 5 minutes and stir before serving.
Best Frozen Margarita! Everytime I serve them I get requests for the recipe.