I haven't played or read enough PbtA to list a "favourite" move, but I like the Theorize move from Brindlewood Bay:

When the Mavens have an open, freewheeling discussion about the solution to a mystery based on the clues they have uncovered and reach a consensus, roll 2d6 plus the number of Clues found, minus the mystery’s complexity.
On a 10+, it’s the correct solution. The Keeper will provide an opportunity to take down the culprit or otherwise save the day.
On a 7-9, it’s the correct solution, but the Keeper will either add an unwelcome complication to the solution itself, or present a complicated or dangerous opportunity to take down the culprit and save the day.
On a 6-, the solution is incorrect, and the Keeper reacts.

I also like how that game's Day and Night moves tweak the typical "Defy Danger" move.