True connoisseurs recognise Rosemary's Baby as the finest horror film of all time
Good film that, yeah. Roman Polanski I believe? The Ninth Gate is another good Polanski horror, albeit a bit hammy in parts.
The Fearless Vampire Killers, starring the ill fated Sharon Tate, is worth a watch. More comedy than horror, but the “dance of the dead” Ball scene at the end is genuinely scary.