Hey
@Angie, really love this question. People's favourite books can really say a lot about their personality and priorities. Thanks for opening and for tagging me.
The Metro books. The first one, 2033, being the strongest. I feel a bit embarrassed that my favourite books also got adapted into games, and that's how i first encountered them, but the books just have so much to offer that the games never could. They're a series of odyssey tales chock-full of philosophy, personal meditations on life and identity, and cosmic/existential horror.
I particularly love Khan's musings on how time is a purely subjective concept, because how long is a day underground, or in the void of space? What time is it on the International Space Station? Probably depends which crew member you ask. And in the station where Artyom encounters him, society operates on the same principle. One man's morning is another's afternoon, which is another's middle of the night.
The books definitely aren't everyone's cup of tea, cos they're extremely bleak in setting and plot. But for people who are down for contemplative if grim odyssey tales, i'd say they're actually some of the best out there.