Ghostwatch
The BBC's perilously clever haunted-house mockumentary might be considered the granddaddy of found footage horror. A television crew makes the mistake of investigating (and live-broadcasting) an unassuming family home where strange disturbances have been taking place. Very slowly, things begin to go terribly wrong. The original broadcast of this deftly scripted frightfest, which appeared with no disclaimers or indications of its fictional nature, genuinely terrified many British watchers who assumed it was real. You can't have quite the same experience, but you'll still be creeped out.