Fiction:
* Three Men in a Boat (To Say Nothing of the Dog) by Jerome K. Jerome (Humorous)
* The Three Musketeers by Alexandre Dumas (Historical Fiction)
* The Three Body Problem by Cixin Liu (Science Fiction)
* The Three Lives of Thomasina by Michel de Montaigne (Fantasy)
* Three Cups of Deceit by Brenda Joyce (Romance)
* Three Days of the Condor by James Grady (Thriller)
Non-Fiction:
* The Three-Body Problem by Cixin Liu (Science Fiction)
* The Three Pillars of Sustainability by John Elkington (Business)
* Three Cups of Tea by Greg Mortenson (Memoir)
* The Three-Legged Stool by Peter Drucker (Management)
Children's Literature:
* The Three Little Pigs (Folk Tale)
* The Three Billy Goats Gruff (Folk Tale)
* The Three Bears (Folk Tale)
* The Three Princes of Serendip (Fantasy)
Other:
* The Three Stigmata of Palmer Eldritch by Philip K. Dick (Science Fiction)
* The Three Faces of Eve by Thigpen & Cleckley (Psychology)
More Specific Requests:
* By a specific author: Tell me the author and I can give you more specific titles.
* A specific genre: Do you want something more specific than "Fiction" or "Non-fiction"? For example, "Fantasy" or "Historical Fiction"?
* A specific theme: Are you looking for books about family, love, adventure, or something else?
Let me know if you have any more details, and I'll try to give you even more relevant examples!