Christmas dinner on Concorde in '88. I won a competition for one of those pleasure flights that they did. As it turned out they served Crimbo dinner while we were still on the deck. A great experience, managed to get up to Mach 2.02 and FL600 (!) and you really can see the curvature of the Earth through slightly champagne fogged eyes.
Have flown from there many times since but I thought it was a pleasant introduction to Heathrow.