You guys are listing some great examples.
I really dislike when guests are super-rude to the CMs who are working hard to help us have a great day. How many times have you seen a rude guest treat a CM like a dog? I was once behind a rude, nasty guest and I told him to chill out, the CM didn't make the rules. This guy was a freak, but he turned around and all of a sudden he didn't want to lip off when his target could speak freely, unlike the CMs. After he left the line, the CM was cool, and I apologized that those kind of things could happen.