The cooks.com site has a variety of slushie recipes.
Cooks.com - Recipes - Slushies
Personally, I like the following three:
Strawberry Banana Cooler
2 cups unsweetened orange juice
1/2 cup whole frozen strawberries
1 banana, sliced
4 ice cubes
Blend everything until smooth. Makes about 4 servings.
Vanilla Fruit Smoothie
1 cup frozen strawberries, bananas, or peaches
1/2 cup lowfat vanilla yogurt
1 tablespoon frozen apple juice concentrate
Blend everything until smooth. Makes 1 serving.
Fruit Smoothie
1 cup fat free vanilla yogurt
1/2 cup frozen strawberries
1/2 cup frozen banana slices
1/4 cup skim milk
5 ice cubes
Blend everything until smooth. Makes 2 servings.