I was really envious when my father, a retired RAF pilot, told me that he had been invited into the cockpit for a 747 landing at SIN when on the way to an RAF reunion in Oz. (Rather different to the piston engined aircraft he landed there.) But then he was no ordinary passenger.
Then, a few years later, having been allowed into the cockpit I was invited back for the landing at JFK which is very interesting in a crosswind!
A really nice experience! Ah those were the days!