Well honestly I've gotten in the habit of not allowing myself to eat before I study (Mainly because after I eat dinner I just naturally want to pass out for hours), so my motivation is supper! However I wouldn't really recommend this to anyone. I guess I kind of realized how twisted it sounds after I typed and reread my comment. As for long term motivation......of course its the satisfaction of having a career that I'm passionate about and having financial freedom burdens caused by insurmountable debt.
I go to Oakley.com and build a pair of custom sunglasses that I will buy myself if I reach my target score on the LSAT. I'm usually a tight wad so $155 glasses is a big present for myself. This is my short term motivation.