Cinema has always had a thing for aliens. In fact, one of the first silent movies ever, A Trip to the Moon (1902), featured astronauts battling a lunar species called the Selenites. Since then, alien encounters have run the gamut from heartwarming (E.T.) to thought-provoking (District 9) to downright terrifying (Alien). Of course, one would hope that if you had a choice in real life, choosing a benevolent intergalactic meeting would be best. But which extra-terrestrial encounter from the movies would you rank as the greatest?