I don't generally have physical rewards for myself. The first draft of my first book took me years to write and I thought at the end of it I'd go out for dinner or have a celebratory glass of wine or something. But I didn't. Not sure why. What I did do was post obnoxious celebratory statements on facebook (and possibly twitter), then pester my family and boyfriend (now husband) by bragging about how awesome I was.
I get work done and life goes on.
However, if I ever manage to get published, there will be a party for the ages. Roller coasters, fireworks, cliff diving, and unicorn party favors. (Or, I'll just call everyone I know and brag my pants off).
Honestly, I don't do this for the rewards. Finishing a chapter is a reward in and of itself. Getting published is the most awesome reward ever. I don't know that a cupcake would live up to that. ;)
39. Holy Fools - Joanne Harris
40. Battle Royale - Koushun Takami