These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Crowning Moment Of Awesome: For the team, it's the attack on the Principal. For Sam, it's revealing Sean Bean's character's deception.
"You wanna talk about an ambush? I just ambushed you with a cup of coffee!"
Like You Would Really Do It: Subverted. Gregor assumes the Russians will let him live to spare the life of Natacha, but is proven wrong 45 seconds later.
What an Idiot: While we never learn Sean Bean's true background, it's clear that he is under-qualified for the task at hand, walking directly into an ambush at the arms dealers, and then plotting a sneak attack than involves 2 machine gunners DIRECTLY across from each other.
Fridge Brilliance: Miller practically tells us the The Reveal in the first few pages. We see the Ronin and Ozaki fighting demons and then it cuts to the future where we see Billy watching TV. On the first read, we naturally just assume that it is a time cut. We don't see what Billy is watching and don't stop to think that all of this is a part of the same scene and that the moments with Ronin in ancient Japan were just the program he was watching.