I did have a very good one the other week flying back IAD-LHR, mind.
CSM came back to Y to look for me but ended up giving this pretty long winded greeting to the guy in front who seemed a little perplexed but was quite happily going along with it all. I quietly pointed out just as she was about to turn away that I'm actually Mr ****. She was very apologetic and the guy in front was then quick to point out through a big grin, that yes he was just playing along with it all. Anyway, this lady by the name of Claire was just fantastic. She returned about 5 minutes later and whispered to me that there's an empty seat in WTP and if I would like it. I of course obliged considering I hadn't managed to get the usual exit row on this particular flight and she was also offering me the first row. She asked me to follow her lead, so I grabbed my stuff and we got to the seat at which point she quite vocally said, "Terribly sorry about the defective seat in 27H Mr ****- I will have make sure to have it logged for you, in the meantime hope this is alright for you" with a wink.
On an overnight flight, I can imagine the CC has to deal with quite a few unresponsive, pretty groggy and grumpy souls down the back but I could hear her as I woke up, chatting to fellow passengers, doing everything with a smile, checking if people had enough rest etc. It all came across so genuine. Then on the way out, as I was walking to exit, she asked if I managed to get a little more sleep myself and wished me a great day. Outstanding and when BA is like this- you can't beat it. Golden ticket issued.