What would you say is your favorite single work by Tolstoy?
Hmm that's a great question. War and Peace is obviously his most comprehensive work, and my favorite novel of his. However, I would say that The Death of Ivan Ilyich, a short novella, is my favorite writing of his. It more has to do with nostalgia than anything. It was the first time I read him and my eyes were open to the depth that he offered. Have you ever read any Tolstoy?
The Death of Ivan Ilyich actually exists in an operatic adaptation by John Young and Alan Olejniczak! You should check it out.
I'm ashamed to say I've never heard of it, but I do appreciate opera so opera plus Tolstoy would be a dream come true. I know a lot of people hate adaptations, but I think they are helpful in bringing complex literature to a wider audience.
That's an interesting perspective! Speaking of adaptations, are you familiar with Prokofiev's War and Peace? It is a massive piece, lasting over four hours!
I am more familiar with the history of it than having actually listened to it. It's on my to-do-list; I just haven't had a chance to get around to it. To think that Prokofiev made that piece of art during the Stalin years where art was heavily suppressed. That must have been scary, never knowing if your music would offend the leader and it would mean your death. 
Those were extremely turbulent times, it must be said. What's interesting is that Lenin was a great admirer of literature, and was intrigued by Tolstoy.
Oh yes! The Bolsheviks loved Tolstoy due to his vow of poverty and critique of the bourgeoisie. However, I do believe that he was co-opted by them and he would not have approved of their violent methods. He was a man of peace. He was more anarcho-socialist than communist. 
It seems as though the controversy surrounding Tolstoy continues to brew. In 2010, an effort was made to have him rehabilitated by the Russian Orthodox Church. Many accuse him of aiding and abetting the Bolsheviks.
Oh yeah! I remembered reading that in the New York Times, a few years ago. I think that is an unfair accusation. He was clearly a pacifist and religious man. Something that the Bolsheviks were not. Plus, he was died in 1910, so he was not even around to see the worse of communism.