Cynthia Nixon's hilariously panicked delivery of Miranda's Squick at a lover asking for a rim job by waggling his ass: "I don't want to do that!"
Samantha has had several, but perhaps her all time funniest was her proclamation about Miranda's son- "That baby is an asshole!"
After yet another disastrous date, a fed-up and hung-over Charlotte loses her temper and starts shrieking, "I've been dating since I was 15! I'm exhausted! WHERE IS HE?" One laughs, but when you realizes that that's 19 years of dating without having found Mr. Right, her frustration is actually pretty understandable.
In one episode Samantha is afraid she might have reached the menopause. She confesses to the other three that she's "actually a little older than the rest of you". Carrie, Miranda and Charlotte all awkwardly avoid her gaze.
In the movie when Carrie makes a half-hearted pun in Mexico Samantha's reaction is priceless.
Samantha: Oh honey, you told a joke! Good for you! *super excited, supportive nod and smile*
The infamous anal sex discussion, where Charlotte panics she doesn't want to be known as the "up the butt girl".