Over the years as I've casually re-listened to a lot of HDTGM episodes, I started to notice some interesting patterns. So naturally I started a spreadsheet to keep track of them. And now I share that spreadsheet here, for your general amusement. It should be editable, if you notice anything to add.
https://docs.google.com/spreadsheets/d/1kK92T86Wr8RcpU-KRhKFVsnwZy0iEf4vrSsXRDJz_1c/edit?usp=sharing
My favorite one is the very first.