Lu-Tze turns out to know Deja-Fu, a martial art involving timebending, alone of all the time monks. And using it to beat the crud out of the son of the personification of Time, now doing mum's job, after extracting a promise from said son to not hurt him. Oh, and the part where he gets his head cut off.
Susan, throughout. She faces down Nanny Ogg, and wins. And gets Nanny Ogg to tell her the whole truth. And that's just part of what she does.
Reexamine that statement. Made. NANNY OGG. Tell. The. Whole. TRUTH. Nanny Ogg, for whom the truth is a reference point, and can think through a corkscrew in a hurricane without touching the sides.
She beats down the auditors with chocolate!
Less world-shaking, but Susan also gets a Crowning Moment of Awesome Teaching off-camera. We'll never know what, exactly, she did to get destructo-tyke Jason to shape up, but it surely rates...
In a similar vein: "one thing a bogey dos not like is Miss finding him".
The moment Myria LeJean rejects her Auditor-ness.
"I was one of them," said Myria LeJean. "Now, I rather think I'm one of me."
Her death could compete with that moment: perfectly diving into a lake of chocolate, naked and holding a silver ladle. Even Kaos admires her style.
The Fifth Horseman, Kaos, thinks his time is past and no-one cares for his attribute anymore. Lu-Tze manages to convince him that chaos is back in again, citing chaos theory and so on, and persuades him to ride out against the Auditors—and, of course, chaos is the one thing they fear most in the universe.
Marco Soto's one exception. Nobody touches the hair.