This is like the one you get at Starbucks, with a little something added.

1 cup double-strength coffee, chilled
4 tsp. sugar
3/4 cup milk
1 tray of ice cubes
2-4 scoops of coffee ice cream

Put everything into the blender.
Blend WELL.
Pour into glass and drink with a straw.

Notes:
I added the coffee ice cream to this recipe to make it richer.
I usually use about 3 scoops of ice cream.

You will need to stop your blender and stir things around with a spoon, and then blend some more. You want to get rid of any ice chips, so it is smooth like a daquiri.

If you don't want so much caffeine you can make your coffee with 1/2 decaf.