For me it's A Storm of Swords by George RR Martin. That shit destroyed me.
The Inner Game of Tennis.
That book changed my life (in Valorant at least), it brought me out of my half year slump.
"Scythe" is very good YA Trilogy, "Project Hail Mary" very good for science based sci-fi, and "Way of Kings" is very good if you like strong worldbuilding and large scale fantasy
I only read books during elementary school, but one that I liked the most and that stayed in my mind was:
The Brothers Lionheart
its kids book, but I was so fascinated of the way they approach topics like death and afterlife for a kids book.