1. Halloween H20
As horror films go, this one really has the mother of all cameos. When Laurie (Jamie Lee Curtis) bumps into school secretary Norma Watson (Janet Leigh), this wink to the audience quickly develops into a full-blown tic. Not only is Norma's line ''I guess everyone's entitled to one good scare'' a classic Halloween throwback but her words of advice to Laurie begin with ''If I could be maternal for a moment...'' The film (and, you assume, the cast) then tries its best to maintain a straight face, perhaps giving the audience time to climb down from the ceiling. Norma retreats to her car parked across the road, a 1957 Ford sedan; registration number NFB 418. Why so specific? Well, let's just say you'll have seen it before. And, as she does so, listen closely for a final flourish in the following clip around the 1:07 mark... https://www.youtube.com/watch?feature=player_detailpage&v=flmGJucqLck