What books do you consider must reads?

So basically I was unschooled, and the amount of books I've read in my life is embarrassingly low. It was never emforced like in a school, and with my family's religious hangups, I never tried getting into new things because I never knew what would be deemed "offensive".

But I'm always interested when I hear people talk about both storycraft and also literary criticism, so I want to take an earnest stab at getting into books.

No real criteria, I don't know what I like so I can't tell you what I'm looking for, other than it needs to be in English or have an English translation. Just wanna know what y'all think would make good or important reading.

ETA holy shit thanks for all the suggestions! Definitely gonna make a list

ETA if I reply extremely late it's because it took me this long to get a library card in my new locale.