Have you done a full calibration yet? Make sure that all your axis are moving the exact distance you tell them too. Also, make sure you are extruding the correct amount of filament. It looks like you are skipping steps. The most common problem for this is loose belts. Your belts should be so tight that they make a noise when you pluck them. Another thing to do is go over all your screws and make sure they are nice and tight. Any vibration from loose screws will cause alignment issues. Lastly, make sure all your bearings are really tight in their holders. If these can flex at all, your smooth rods will sag as you reach the end of your axis.

Have fun,

KDog