I have a fond memory of a flight from FRA to LCY a few years back. Four of us had been at Hockenheim for the weekend covering its annual drag race. I think that we were the only casually-dressed passengers on the flight as everyone else was pretty obviously travelling on business. As is their apparent wont the business travellers were treating the flight attendants with something like contempt, ignoring the safety demo and hardly looking up from behind their newspapers or laptops during service. Us four scruffs on the other hand said please and thank you and gave the FA a smile. After service was complete our FA came to speak to us and asked where we had been and what we had been up to, although she admitted that she had never heard of drag racing she clearly found this group of rapscallion photo-journalists interesting. After chatting to us for a while she disappeared back to her cubby-hole and returned with an armful of extra packets of popcorn and cans of drink all of which she placed squarely on my table. Of course, I was persuaded to share with my colleagues.
I know this doesn't compare with some of the excellent stories in this thread but it makes me smile every time I remember it.