Well... there are lots of things, but standing in front of a mirror without my clothes on and asking myself "Are you still overweight?" usually does it. Because I am!
Wanting to see the number on the scale drop is motivating for me also. I've been stalled for a few weeks now.
The fact that my fasting blood glucose went from 109 to 87 after losing weight and exercising 5-6 days a week also has been great motivation!
Having to buy new clothes because I can no longer wear my old, big ones is great motivation! And reward!
That's all I can think of right now... more if I come up with them!
Jay