Invasion of the Body Snatchers (1956), Invasion of the Body Snatchers (1978), The Invasion, The Faculty, The World’s End etc and so on.  Like Romero’s zombies the pod people (or versions thereof) return every few years to tap into the zeitgeist (communism, psychiatry, the Bush Doctrine, erm, school and chain pubs?) and scare us. Abel Ferrara’s take might not be the most unsettling (1978, if you are interested) but it’s military setting and direction make it the most thrilling version and, in genre cinema, that’s just what the doctor ordered. Meg Tilly is great as that staple of all fiction the ‘untrustworthy step-parent’ and Forest Whitaker steals the show as the crumbling Major Collins.