I remember as a kid in NZ getting to go up to the cockpit of a 747 mid flight (dad was air NZ's no 1 frequent flyer...back in the days when that actually meant something).
Anyway, the best experience was actually just recently. I was waiting to board a Qantas Flight From Sydney to London and I was standing near the bridge with my carry on...which has an aopa sticker on it. I noticed that the flight crew were standing nearby aznd talking and pointing at me.
So eventually the captain comes over and starts chatting to me and asked if I was a pilot. So we chatted for about 10 mins on GA aircraft and how he really missed having the time to fly bug-smashers everywhere. So he asked me my name and thanked me for the chat and that was that.
Anyway, after about 20-30 mins we start boarding and I get up to the front where the lead FA is checking the boarding passes as you step on the plane. I hand her my pass and she says oh Mr ********* The captain would like to extend you the courtesy of a seat in first class!!!!!!
It was a fairly empty flight and they just happened to have some spare seats in first. I loved every min of it...especially on a long flight like that one is!
God Bless that Captain and his PIC authority
Cheers