If you've always found the traditional pain chart inadequate, I highly recommend a trip to Hyperbole and a Half where she's made a new and superior pain chart.
She has also relabeled the traditional one:
0: Haha! I'm not wearing any pants!
2: Awesome! Someone just offered me a free hot dog!
4: Huh. I never knew that about giraffes.
6: I'm sorry about your cat, but can we talk about something else now? I'm bored.
8: The ice cream I bought barely has any cookie dough chunks in it. This is not what I expected and I am disappointed.
10:You hurt my feelings and now I'm crying!