The seamless transition of the Jets walking down the street to dancing in the street.
Watching the Prologue and noticing how the Jets always move from right to left across the screen. The motion—across the basketball court, down the alleys and into the street—is continuous and uninterrupted. But the moment Riff and the Jets meet Bernardo, that movement stops. And when Bernardo walks way from the gang, notice his path of exit: he moves from left to right.It’s the perfect way to underline the importance of that moment; the Jets have met their opposing force. And you'll notice that in all the musical numbers, the gangs always move in opposite directions.
Baby John doing that gunfighter bit at the end of The Jet Song.
Tony: "End your suffering, little man. Why don't you just pack up your gear and move out"?
Riff: "Cause ya ma's hot for me..."
Glad Hand: "I want you all to form two circles. The boys on the outside and the girls on the inside".
Action: "Where will you be"?
The look of outrage on Riff's face when Bernard says : "l would not leave the ladies alone with your kind around".
Anita calling Bernardo "the old married woman".
Bernardo saying goodbye to the Shark Girls with : "Etc, etc."
Anybodys: "I ain't never gonna get married. Too noisy".
A-Rab: "You ain't never gonna get married. Too ugly".
Anybodys: [mimes firing a gun] "Pow!"
A-Rab: "Cracko Jacko! Down goes a teenage hoodlum".
Poor Doc "l have no mind, l'm the village idiot".
Watching the rumble and knowing that out of camera view there's a woman named Betty Wahlberg playing the piano and counting out; Jerry choreographed every single step of that rumble.
After the deaths of Riff and Bernardo there's the big free-for-all fight and suddenly you hear the police sirens - how the various Jets and Sharks snap their heads up to the plinking sound the orchestra makes.
A-rab and Baby John : "A-Rab, you got a hankerchief first? What's wrong with your sleeve"?
The brilliance of Cool, using dance as a metaphor for rage. And their cluster at the end of the number to stare up at the man who threw the bottle.
To Anybodys : "Aw, go wear a skirt. I got scabby knees".
Maria throwing herself over Tony's lifeless body and screaming "Don't you touch him!" when Shrank and Krupke move towards him.
Baby John placing Maria's wrap around her at the end. And then the shot of her kneeling on the ground - all alone.