Probably the simplest yet most startling mindreading effect ever!
Place three cards (one with red circles, one with blue circles and one with yellow circles)
face up on a table. Let your spectator FREELY CHOOSE any color, and he can even change his mind. No matter which color is selected, you reveal that you predicted the right color, and your prediction has been untouched and in full view the entire time!
No skill, no sleights necessary. If you can place cards down on a table, you can do this trick!