I found Dostoyevsky’s “The Brothers Karamazov” and “Crime and Punishment” great.
I discovered Mikhail Bulgakov a couple of years ago. I loved his “Heart of a Dog” and “The Fatal Eggs”.  I’m looking forward to reading “The Master and Margarita” and “The White Guard”.
I plan to read Doctor Zhivago in a not too distant future.

I had to read lots of Russian classics at school. I can't say I liked all of it but some were really good. I've even read some more than I had to. Let me try to list all I've read: Pushkin, Gogol, Turgenev, Chekhov, Tolstoy, Dostoyevsky, Solohov, Ostrovsky, Yesenin, I'm sure I've missed some.

I've read a few novels written by Leo Tolstoy and I really liked them.

I've read some of Solzhenitsyn's works. The Gulag Archipelago is an important book.