Can you recommend any clic fiction novels?

It's a x-mas gift for my brother. His favorite book is the Alchemist. He's into stuff like: The Life of Pi, Celestine prophecy, Da Vinci Cose, Siddartha, Tuesdays with Morrie, etc. He's interested in truth seeking themes. Whether they are older clics or modern clics, it doesn't matter. I would appreciate some help. Thanks.