For me I really do enjoy watching some of the Locking picking lawyers content and he is an expert when it comes to picking locks!
Another few are mental outlaw (although I think everyone knows of him here) and Steven Bridges who makes videos on card counting at casinos and he shows how much he wins/loses from playing
Cracking The Cryptic is amazing. Their videos are so interesting to watch.
They also have great sudoku apps. They’re not free but there are no ads and they come with a lot of great puzzles.