Um... hello? The Matrix?
I don't care if it's unrealistic. Can anyone honestly say you watched that very first fight scene without absolutely being amazed?
"No, Lieutenant. Your men are already dead."
It may seem commonplace or even a little stale now, but I remember seeing the original in the movie theater before the plot was widely known. You knew there was something weird going on, but...
Or how about "Guns. Lots of guns."
Lobby scene