I was playing Halo 3 with a friend and some other random dude, on that "standard" map with the two bases and the river, Valhalla? Anyway, I had a Spartan Laser, was standing in front of the oceanside base aiming at the random dude almost all the way across the map. Just before the beam fired, my friend, who was in a Banshee, hit the ground somewhere halfway. Less than a moment later, I got a double kill. Because a Banshee suddenly came down in the path of my laser.
L4D singleplayer, No Mercy on easy. I pushed a common infected off the edge of the construction area on the top floor. I had a really Looney Tunes vibe about the whole affair, with the infected flailing at me and a moment later just..... disappearing from sight.
One time, in Red Orchestra, I know the map but can't recall the name, I was standing halfway up the stairs in a small shed carrying a Mosin-Nagant bolt-action rifle. I looked to my left and saw a German lying there, I shot him from the hip and killed him. I looked to my right, and another German just walked in, I shot him from the hip and killed him. E.g. I got two kills in a row with a bolt-action rifle from the hip. More luck than anything, but still.
Another time in RO, I was carrying an MG-34 on Zhitomir, I was standing in a small outbuilding with a window looking towards the Krasnaya Apts, and there was one Soviet soldier lying prone on top of the dirt ramp, about 100m away. I aimed my MG from the hip, fired, and killed him in just a few shots. With an MG, from the hip, at 100m.