So many. Tarrasch St Petersburg 1914, Nimzowitsch My System, Reti Masters of the Chessboard, Keres/Kotov The Art of the Middle Game, everything written by Bent Larsen. Plus some books only existing in Danish, Swedish and Norwegian
Best chess books

Good Chess Books for Beginners and Beyond…
https://www.chess.com/blog/RussBell/good-chess-books-for-beginners-and-beyond

Tactics:The Woodpecker Method - https://www.amazon.com/Woodpecker-Method-Axel-Smith/dp/1784830542 - great collection of chess puzzles. All by World Chess Champions.
Chess Training Pocket Book https://www.amazon.com/Chess-Training-Pocket-Book-Comprehensive/dp/1889323225 - another great collection and in pocket size. By the way, I don't understand why there are so few books in this size. There is second book too: https://www.amazon.com/Chess-Training-Pocket-Book-Positions/dp/1889323179/Game collection:
Winning by Nigel Short: https://www.amazon.com/Winning-Nigel-Short/dp/178483159X - The best collection of lots I have ever studied. Nigel Short shows every game he played in the tournament - you can see how he thought, how he chose his opening, what he thought of his opponent, etc. Because of this, even the weaker games are there and you also see how to play and think in uncomfortable positions.
OpeningThis is quite complicated because each player has his own repertoire.

I enjoyed the two Piatigorsky Cup tournament books and Bronstein’s book of the 1952 Zurich tournament.
Anybody have any favorite chess books? I know mine is from tactics to strategy by GM Thomas Luther.