Well in my case Lewis' "Chronicles of Narnia" stand out as my favorites, of those "The Last Battle", "The Magician's Nephew", and "The Voyage of The Dawn Treader" stand out for me, but not by much, for the whole thing can read/viewed as a single volume, as easily as if it were all within one cover, which is impressive. However, I have not read those lately, or much of anything with an actual physical cover on it. Being a researcher, much of what I read online tends to be of a more obscure nature, texts/articles on secret societies, F.O.I.A. released documents, government and military manuals etc, articles addressing such abominations as trans-humanism and perversity that the puppets of evil are trying to legalize, many materials that may be considered bleak or depressing for people, despite their informational content. There is also Mythology and Folklore (such as "Oregon's Ghosts and Monsters") in that mix, learning of various so-called gods, the cosmology and theology of other cultures etc. which is not to say I'm void of classics, things such as "Treasure Island", "20,000 Leagues Under The Sea", Sherlock Holmes mysteries (Of which, "The Hound of the Baskervilles" was my favorite), and even "The Strange Case of Dr. Jekyll & Mr. Hyde" prove informative and insightful.
As an aside, anyone that has trouble with spooks/devilish entities or is interested in their modes of operation should give "The Screwtape Letters" (Also by Lewis) a read. Finally, there is also a space trilogy that Lewis wrote, and while it does provide a good reason why there are not "aliens" visiting earth, I found one bit in the second book be a bit "heavy", not so much the reading, but rather "heavy" in the sense of emotional situation with dire consequences. (The Trilogy, for those curious is "Out of the Silent Planet", "Perelandra", and "That Hideous Strength".) I have yet to finish it.
P.S. Tolkien's works are also fun, "The Hobbit", the Lord of the Rings series and "The Silmarillion" All well worth reading in their entirety.