Let me do a country vise list and will start with the places I have been to then will continue with the places I intend to go sometime soon.
Laos
When I came to know that I am supposed to go to Laos for an official trip, more than the fact that I would have to slog my ass off, I was excited that I will get 2 weekends to myself which meant I could cover Laos on 1 weekend and Cambodia on the other.