I used to love reading massive purple prosey, fluffy rpg tomes with complex rules that took work to parse. But nowadays the reading rpg books for fun has lost its lustre.
My goto game is Savage Worlds. Even though it's not totally stripped, its core and companions are pretty thin. Lists of edges, spells etc are short and managable, and the books are readable as actual books of rules and gaming frameworks. It's paid by content rather than paid by words.
My second love is Dungeon Crawl Classics. The core is phat, but most of that are tables that is automated in Foundry, hence I don't need to memorize them. Actual rule sections are short and intuitive, and the book manage to mediate the intended playstyle without hundreds of pages of fluff.
But I'm more and more drawn to even more stripped OSR stuff. Probably that goes hand in hand with the evolution of my GMing style and preference. Just give me a good, short frame of rules, and let me and my table make fun sh*t up.