Where does the ground shake the most during an earthquake

The strongest shaking is towards the center of the actual earthquake which it is called the focus. The epicenter of an earthquake is the point on the Earth's surface above the focus or hypocenter which is the point within the Earth where the rupture occurs. As such the epicenter is the closest point to this. 

At the focus. This is where the two plates collide together and rub together causing friction which is released causing the ground to shake