i always take people through the plots in the structure that they occur in the film. eg - Die Hard. John arrives at the building, building is taken over, John kills this man, he is this man's brother, John does this. A police man comes....etc etc
it makes your script sound much duller than it probably is, but this a) encourages you to improve the script further and b) gives the reader an definitive view of what is going to happen.
most i have read always try to end with a general advertising statement. eg - for Love Actually. 'a charming take on love in the modern city of deadlines'
the greatest i have ever read include an analysis of the potential appeall of the film to target audiences, even going so far as to reveal how they would identify with main characters, and of course, your Unique Selling Point.
good luck