Best example is probably the "Tonight" reprise, particularly when all five parts come together at the end. On paper, it's incredibly chaotic. In practise (as this troper can attest, having been in it last year), it's positively GLORIOUS.
In that same scene when she screams at Shrank not to touch Tony. And for once, the bigoted jerk keeps his mouth shut and steps back. The grudging shred of respect he has for her in that moment is evident.
Anita is a badass in "America," telling off Rosalia in the play and Bernardo in the movie for dissing the titular country in which she feels free and liberated with flawless sass, while dancing like a mofo with her girlfriends. Said friends get awesome points in this song too, for backing up Anita and sassing right alongside her. And that's got even getting started on the song's dance sequence.