A: The title sequence to North by Northwest!
Right from the title sequence, Alfred Hitchcock tells the audience an open secret: This will be fun. The titles depict a patterned building and flying text with names of all the important players in the film. This is self-awareness to the greatest extent, with Bernard Herrman's booming score, one can only imagine the frenzy and fun, despite the picture's plot not even beginning.
So when the plot does begin, we feel within the first 10 minutes that this isn't Vertigo Hitchcock, but this is instead 39 Steps Hitchcock. We see Roger O. Thornhill, an anti-Don Draper, a Manhattan Ad-man with so much on his plate that a day off would do wonders. Ironically, he gets his free time when he is kidnapped rather smoothly from a dinner meeting by men of Phillip Vandamm (James Mason, in a sinister role), a Communist spy in the USA. Let me remind you that this is still within the film's first 10 minutes.