Hab brought up a good point. We've all gotten poor service at some point at a restaurant or other service establishment, but this is a two way street - there are probably just as many nightmare customer stories as there are nightmare waitress tales. Back in college, one of my old housemates worked as a waitress and used to tell us these horror stories about Denny's and this other 24 cafe she worked at. She was rather buxom and had several instances where male customers would make spectacularly rude comments about this fact or even paw her without provocation. Other memorables would be the 2 am students-leaving-the-bar crowd which would on occasion beef all over the table, booth, or once even on her shoes. It sounded like hardly a day would go by where someone wouldn't ditch without leaving a tip or paying the bill - even though there were no apparent problems with the food or service.
I'm guessing she had it worse than most just because of the quality of restaurant she was working and also that it was a college town. Maybe someone who's waited tables can confirm.
Anywho, I'm sure lots of us have worked retail at some point and have our supply of nightmare customer stories. Let's hear 'em.