Capping a point while some Warlock with a Sniper Rifle off in the distance attempted to climb his perch. As soon as he turned around, I pulled off a headshot with my own Sniper Rifle. It had taken him the entire neutralizing and capping of the point to get up there. Close second is hitting someone near a cliff with Solar Wind (Sunsinger) and getting the melee kill for it as they fall off the map.