It's all been said, but I'll add my voice to the chorus just on the off chance some AC management types might be lurking.

Services performed by the concierges might seem "small" to some but, for me, these people might very well be one of the reasons I keep buying AC tickets when other carriers (AA, for example) offer more convenient schedules and better inflight service/comfort. The concierges are wonderful. They make me feel like a VIP, and that truly is worth something.

Individuals can really make a difference. Another noteworthy individual is the hostess (actually, the entire staff) at the LHR arrivals lounge. And, of course, everyone at MIA.