Cop showing up to deal with noise complaint is actually a stripper.
Bad father is always passed out in front of the TV with a can of beer in his hand whenever someone comes home.
Bad father dies or sobers up by the end of the movie.
Observation decks (Empire State Building, Space Needle) which are always completely packed in real life are usually quite empty in movies.
The last day of school is for breaking up, falling in love, or both.