Oblivion's drone. I'm in love ... Although the sounds and effects are a clear rip off from robocop's ED209, still the drones were great. Besides flying in straight lines, having quadruple machine guns which can fire backwards, scan beams lifted off from the movie Aliens 2 (at the start, when they got Ripley off her ship), and red robot eyes (from Terminator, if any one really has to ask), still these drones were great.
The obvious reason is this. They were single minded killing machines. Sometimes, in our day and age where every motive has to be questioned and every act has to be analyzed, its nice encountering a bad ass machine which does one thing only - search for and kill humans (and reluctantly refrains from killing the humans which maintain it ...).
Like I said, pure love for a pure killing machine.