for me personally, Advanced Concepts of Poker: A Guaranteed Income for Life by Frank Wallace. It takes a different approach from the average book taking you alongside a grinder who runs home games and travels to casinos. The depth in which he studies his opponents, their incomes, the game, cheating, awareness and the way he explains his methods of keeping players in the game, not giving too much info, and taking proper notes and adjustments really showed me how much effort people are putting into poker and gave me motivation to start being more mindful with my playing and learning. It still does have standard hands and quizzes/explanations on hands and ranges but it isn't the main focus of the book.