Two years ago I was flying with my family to LAX from YYZ through ORD on UA. It was March break and the flight to ORD was delayed. So much so that we were going to miss our connection. As it was Friday night, there were very few options. The UA agent dropped everything and tried to get us to LAX that night. Ultimately he couldn't get 4 seats that night but he was able to protect us the next morning from ORD so we spent the night in ORD carried on in the morning.
About a month later I was flying UA again and the same agent was working the flight. I went up to him and thanked him again for all his efforts that night. He remembered me and really appreciated me taking the time to thank him. The really good employees do exist and as customers it is important to recognize what they do so that they continue to do it.