The Selfish Gene (Dawkins) - helped nudge me over the line in terms of really identifying as an atheist, by satisfactorily refuting any lingering hints of the "irreducible complexity" argument that were lodged in my brain.
The Fountainhead (Rand) - I actually saw the movie before reading the book, but the Howard Roark character is a real role model character to me.
The Four Steps to the Epiphany (Blank) - As far as I'm concerned, this is THE book for startup founders / entrepreneurs. Very detailed, very logical, iterative process for building a company, defining a product, finding customer base, etc.
Nineteen Eighty-four (Orwell) - Read this one my senior year in High School and it left a profound mark on my psyche. I was already leaning towards a very individualistic / libertarian worldview, but 1984 really enflamed my hatred for big, heavy-handed, oppressive government(s).
https://en.m.wikipedia.org/wiki/One_Two_Three..._Infinity
Name drops Neil deGrasse Tyson (Is he that old?)
Internet Archive has a 1961 copy.
https://ia801305.us.archive.org/19/items/OneTwoThreeInfinity...
The Nature of the Universe, by Fred Hoyle, as well.
Flatland by Edwin Abbott - if it doesn't break your brain thinking about seeing in shadows of reality, and never being able to all of anything at once, you need to read it again
A Brief History of Time by Stephen Hawking - read it a couple years ago on vacation as my "beach read". Thought a bunch of what he wrote was pretty interesting/entertaining (though I disagree with some of his presuppositions and/or conclusions). Also made watching Tenet more enjoyable. And gave me an idea for a story (that I do not know how to write) wherein there is a class of people who only "remember the future" - they know what is going to happen before it happens, but as soon as it happens, they forget ... iow, they experience time half-backwards (they live it forward, but can not recall anything once it's occurred - it's all a "prediction" or "guess" to them...just like the future is to everyone else)
Red Storm Rising by Tom Clancy - contemplating a 100% 'conventional' WWIII, Clancy does a couple interesting things in the story that I have often wondered why they have not been talked about elsewhere (maybe they have in classified circles, but certainly not anywhere I have run across them) ... notably, using a A-10 Thunderbolts flying close to the deck over the ocean to strafe thin-hulled warships
Learning Basic for Tandy Computers by David A Lien - first programming book I ever had/used (it's even available on Internet Archive - https://archive.org/details/LearningBasicForTandyComputers/) ... got me into programming/scripting when I was about 10
The book that popped into my head from my subconscious when I read the question was 'Catch-22'. I was a teenager when I read that. It taught me to be less naive, more cynical. It was also very, very funny. And it tickled my offbeat Sense of Humor.
Left around at home to indoctrinate me into "stuff" at age 8. Ended up being the first sparkle of my rebellion against "stuff".