'Gulag Archipelago' [Aleksandr Solzhenitsyn] vs. 'War and Peace' [Leo Tolstoy]

The two books in the title are next on my reading list, and I can't decide which one I want to read!

Some books I've read recently that I enjoy are 'The Civil War as a Theological Crisis' by Mark Noll , 'Mere Christianity' by C.S. Lewis , 'The Reason for God : Belief in an Age of Skepticism' by Timothy Keller, and i'm currently reading 'A Tale of Two Cities' by Charles Dickens which I enjoy quite a bit so far (really like his descriptive and fluent writing style as it makes the book seem like a movie).

Which one would you recommend I read first based on your personal opinions and maybe taking into consideration the recent books i've read?