I had the opportunity to sit in the cockpit for landing on a LH 744 flight into MUC last year.

I had been sitting in F, and asked during the flight if I could visit the cockpit. I sat and talked to the guys for ~ 1 hour, and as I was getting ready to leave, I asked the F/O and relief pilot (who were flying at the time) whether the Captain ever permitted pax to ride jumpseat for landing. They said they assumed there would be no problem, and so 20 minutes before landing, the relief pilot came back to my seat and brought me up for the landing.

One of the greatest experiences of my life. Honestly (I'm a student pilot).

Greg