Well, my absolute favorite is Vladislav Krapivin. There's no question about it.
Zamyatin's "We" really resonated with me, as did the very psychological Dostoevsky, I love Goncharov, and I enjoyed Bulgakov (I especially love "The White Guard").
"We" is a gem! My father is a mathematician, and he was impressed by how the protagonist views life through the prism of mathematics. It's such unusual poetry, but I find it very relatable.
By the way, dystopia is my favorite genre. And the most realistic of all subgenres of science fiction. It's especially interesting to read dystopias from the past (for example, Wells' "When the Sleeper Wakes" or Huxley's "Brave New World") - almost 80% of the "incredible horrors" turn out to be true, so draw your own conclusions.
I think I was the only one in our class who read Goncharov outside of the curriculum; I really like his "O" trilogy, although for some reason, he's not very popular. But he wrote so well!
There's nothing to say about Bulgakov; he's a classic.
As for Dostoevsky, you have to read him, apparently, not just once to understand. What is unclear and unappealing at first becomes special nuances, and you read it with close attention on the 2nd, 3rd, or 5th time. I like books and authors that you have to reread to fully understand, to feel.
