I have two favorite smoothies:

Frosty Basil Lemonade Smoothie

3 cups water
1 1/2 lemons peeled, halved and seeded
1/4 sweetener (sugar) I use Splenda because of diabetes
1/2 cup basil leaves
1 cup ice cubes

Cucumber Melon Smoothie

1/4 cup soy milk
1 cup green seedless grapes
1 1/2 cups cantaloupe chunks
1/2 cup cucumber peeled and chopped
1 small lime, peeled (cut in half is easier)
1 cup ice cubes

Both recipes from the Vitamix Book