My personal favorite image of 2015 has been taken at the abandoned Casino at the Bokor Mountain, Cambodia.
I noticed some kids, who were playing hide and seek inside the Casino. One kid hide behind the wall, and I knew that sooner or later he will look down the stairs to see if his friends are coming... so I just was there, framed the image, exposed it... and waited. And then the kid came out... click... I got it