I am just the ballast in the back but here goes. No wait a minute, I don't think I'm allowed to tell about the most memorable.
Second most memorable?
Had to hold off from a landing site because of engineering activity. So here we are in a remote (from Gatwick) part of the UK on a beautiful day with wonderful views of sea and mountain all around. Shall we circle for ages and look at the beautiful views? No. How about sneaking up this glen, where nobody knows where we are, and practising autorotations? 'Grounds coming up awfully fast mate.' <Yes, it does that.> 'Holy f.....'