Any of the classics, no matter if Russian, English, Chinese or whatever. I have a number of literature classics lying dead in a drawer after my aunt died. I wanted to donate the whole 100+ kg of them to a local library.

If I had to pick one, I'd probably be Tolstoy. Why?

'cause they're classics for a reason. They're a calcification of the vast human experience. Everyone should get the opportunity to read them.