William de Worde uses the power of the press to prevent the Guild of Engravers and the zombie lawyer Mr. Slant from shutting down his paper, merely by having his printer Mr. Goodmountain set their exact words in type as they say them:
He scores another over Mr. Slant at the end, blackmailing him into being The Times's lawyer, gratis. And probably forever.
Let's just say every instance of William pulling the "I'm just being an honest reporter noting your every word" act on people trying to pull something shady.
When Otto the vampire appears in Lord De Worde's estate and saves William. First he taunts De Worde's goons while launching them through the air with his punches, including asking why they didn't want to fight even when he was using their "civilized fisticuffs". Then he lifts Lord De Worde into the air, rips off his black ribbon of blood temperance and says (paraphrased and de-accented): "William doesn't want me to bite you, he says I am a good person. The question I have to ask myself is: How good am I? Or do I only have to ask myself, am I better than you?
He never liked cocoa, anyway.
To make this even more awesome, he does the last part with a longsword through his chest. His response to this is to comment on how he can't seem to keep his shirts from being ruined.
Heck, William standing up to Lord De Worde in the first place is pretty badass. "The truth has got its boots on," he said, "It's going to start kicking." (A followup to the Arc Words of "A lie can run halfway around the world before the truth has its boots on.")
Taking into account his credentials (see Making Money), when the New Firm (Mr. Pin and Mr. Tulip) intimidate Mr. Slant, an undead zombie lawyer who actually prosecuted his own murderers, and subsequently all others who tried it was pretty badass. How do they do this? He's undead. He'll come back again and again. They realize one thing that no-one else did — zombies are very, very flammable.
I've always liked William De Worde's final interaction with Lord Vetinari. With a single question he forces Lord Vetinari to attend a social function that he clearly would prefer to miss, made that wedding into possible the social event of the year, made his job much easier by filling inches and paid back one Harry King for his previous help with interest.
Well, not so much forced him, as it pleased Vetinari to let William make the request, and to get to see lots of nobles standing there, all stately, for Harry King's daughter's wedding. Where he would be fine attending, but they will all be uncomfortable but too polite to say anything. Like Vimes, he takes his small vindictive pelasures of chance without comment, except internal. But William getting just a bit cheeky with Vetinari was definitely worth the entire book, to be honest.