If you liked The Da Vinci Code by Dan Brown, you might enjoy one of these books:
The Confessor by Daniel Silva
This book is part of a series featuring art restorer and Israeli agent Gabriel Allon. After the assassination of a Munich writer, Allon and Vatican priest Pietro embark on dangerous journeys, revealing long-buried secrets affecting the fates of millions. Meanwhile, the pope vows to uncover the truth about the church's response to the Holocaust in this multilayered-plot.
The Eight by Katherine Neville
During the French Revolution, a young novice risks her life to keep a jeweled chess set that Moors gave Charlemagne; in the 20th century, a computer expert and a chess master try to solve its mystery. The suspenseful narrative contains many puzzles, crosswords, and cryptograms, which should appeal to fans of Robert Langdon’s adventures.
The Eighth Day by John Case
P.I. Danny Cray is hired to discover who is behind a scheme to destroy the reputation of a notorious billionaire—an assignment that hurls him into a sinister world where nothing is what it seems. Dan Brown enthusiasts will love the settings of this riveting thriller—from the streets of D.C. to the Vatican Library to an entire city buried deep under eastern Turkey.
The Expected One by Kathleen McGowan
Maureen Pascal gets mixed up in a quest to gain control of a priceless series of scrolls, written in the first century by Mary Magdalene and hidden in France. Like Langdon, Pascal is an engagingly-drawn university lecturer and author. This book is notable for its hauntingly real depiction of biblical characters and detailed description of biblical history.
Labyrinth by Kate Mosse
Alice, a volunteer at an archaeological dig, becomes a target after discovering a pair of crumbling skeletons in the Pyrenees, while 800 years in the past, Alais, the daughter of a crusader, must safeguard the location of the Holy Grail. Epic adventure weaves together the present and the past in this page-turner.
The Rule of Four by Ian Caldwell & Dustin Thomason
Trying to decipher an ancient text that weaves a mathematical labyrinth within a love story, two students at Princeton obtain a diary that may contain the key to the code. When a fellow researcher is killed, they realize that the book contains a dangerous secret. Riddles, romance, and Renaissance mysteries—oh my!
The Secret Supper by Javier Sierra
It is 1497. Sent to oversee the completion of Da Vinci's "The Last Supper," Dominican inquisitor Fray Agustin Leyre investigates the artist’s omission of key elements and use of symbolic imagery, which suggests that there is a coded message in the painting. This is an interesting historical twist on the mysterious work of Leonardo Da Vinci.
The Sign by Raymond Khoury
When a scientific expedition is swallowed up by a shimmering sphere of light during a live CNN report, a viewer in a dusty Egyptian bar recognizes the phenomenon, which is declared by some as proof of God's existence. Unrelenting action and a suitably twisted ending combined with a powerful message make for a compelling read.
The Templar Legacy by Steve Berry
By 1311, the last Templar master had been burnt at the stake—or so it has been assumed. Now former secret agent Cotton Malone must solve a mystery of the lost 14th century Templar riches, before the evil latter-day Templar Raymond de Roquefort, who will do anything to keep their secrets, prevails. This is a complex but extremely readable thriller.
The Testament by Eric Van Lustbader
After his father's death in a mysterious explosion, "Bravo" Shaw discovers that his dad had been a member of a secret sect tasked with preserving an ancient cache of documents, allegedly written by Christ himself, that could reshape all of Christianity. More Jason Bourne than Robert Langdon, this story will appeal more to the action fan than the puzzle fan.
Also by Dan Brown:
Angels & Demons
In the first novel to feature Harvard professor and symbologist Robert Langdon, a famous physicist is found murdered. This seems to be the work of the Illuminati, a secret brotherhood presumed extinct for nearly 400 years. With beautiful Italian scientist Vittoria Vetra, Langdon embarks on a dangerous mission against an invisible enemy to save the Vatican. This novel features all the heart-stopping suspense and well-drawn characters that Brown fans expect.
The Lost Symbol
In the newest Robert Langdon novel, the discovery of a mysterious object in the U.S. Capitol building and a subsequent kidnapping lead Langdon into a web of mysterious codes, secret locations, and hidden knowledge. With the fastest moving plot of the series, all of the action takes place over a 12-hour period.
On the eve of a presidential race in which NASA's budget is a pivotal issue, the space agency announces the discovery of an ancient meteorite filled with fossils deep in the Arctic ice. This is a very different Dan Brown, but with convincing settings, likeable and hateful characters, sophisticated scientific and military details, and a breakneck pace, it’s still a must-read.