Now I could do a long write up about a great abdominal routine, but instead I found this video and gave it a try, and after a good solid testing I have decided to share this with you all.
The one exercise I love for the abs which I think is also necessary for a complete abdominal workout is this:
Sit on the edge of your bed, balancing your whole body on your butt, leaning back to about 45degrees off the bed, and raise your feet just slightly off the floor. extend your legs till they are fully straight, now bring your knees to your chest slowly and controlled, do not allow your back to touch the mattress or your feet to touch the floor. As David says in the video below it is not about speed or high reps, but about control.