Gosh that's a tough one - there are so many! If I had to choose one, I would tell you about the time that my brother and I backpacked around Myanmar (Burma).
It was 2011, and only shortly after the travel ban to the country had been lifted. We travelled to a country that westerners had not been welcome in for many years, which allowed us to have one of the most unique travel experiences I could ever imagine. Throughout our travels there, whether we were in towns or backwaters, people came up to us to say hello. Many people touched my blonde hair, asking what color that was and how it came to be that way. One man bought us a drink to thank us for coming to his country. We met monks whose temples had been attacked by the army, and who had risen up to overcome the dictatorship.
There was no internet access or phone signal, so we travelled spontaneously, unable to book anything in advance or make any plans. We travelled simply, around an exceptional country that had no other foreigners as far as the eye could see. We had incredible scenery, history, culture and cities almost all to ourselves. It is a trip that I will never forget.