The original Omen was definitely a ground breaking movie for its time. Rosemarys Baby was kind of the start of introducing the idea of an evil child, but The Omen was kind of the first to sculpt a character. The Exorsist was released three years earlier than the Omen but 'Regan' was a pre-teen, not really a child. I agree with Brian too, the following movies were worth watching and was a good franchise at the time! Loved the era of suspense and horror during that time period!