I have just finished reading Alister McGrath's C. S. Lewis - A Life (Hodder & Stoughton, 2013), written to mark the 50th anniversary of Lewis's death.
Lewis was, to me, clearly a remarkable and fascinating character - I studied him in a small way a few years ago.
Those of his works that most readily spring to my mind are the "Chronicles of Narnia", "Mere Christianity" and "The Screwtape Letters", though it would be easy to make other suggestions as to his most noted works.
However, what most came to me through this biography was his wish to share relevant and appropriate faith. As McGrath puts it near the end of the book, "He has come to be seen as a trustworthy, intelligent, and above all accessible representative of a theologically and culturally attractive vision of the Christian faith (p. 371) .... Lewis is seen to enrich and extend faith, without diluting it (p. 375)."
Whatever anyone might think of Lewis, there are some aspirations to live up to.