Congratulations to Joel David Hamkins who on (I think!) the 27th November 2022, was the first MathOverflow user to pass 200k reputation! Since Joel joined on the 19th November 2009, he has supplied 1746 answers, and asked 93 questions.
On the occasion of passing 100k reputation, Joel wrote an essay about how he views MathOverflow.
Since such an announcement is not really a question, how about this:
What is your favourite post by JDH? It could be an Answer or a Question.