Dan Brown write really good mysteries, he writes commercially SUCCESSFUL mysteries that have also found an audience on the big screen.
His most famous effort is The Da Vinci Code. Two of his other novels are Angels and Demons and The Lost Symbol. All of these involve "secret" or hidden symbolism, whether that of the Roman Catholic church or the Freemasons, or The Templars. His main character is Robert Langdon, "symbologist" from Harvard University.
Although these were very successful, they were also a controversial mix of facts, history, conjecture and fiction. In other words, all the traits of a great read.
I found two of Dan Brown's other novels to be Really good, attention-getters, edge of the seat, thrillers. They are Deception Point and Digital Fortress. I encourage fans of the mystery genre to check out reviews of all the Dan Brown novels. And, of course, I am providing links to the Amazon Dan Brown Page. Enjoy.
Incidentally, there are two authors named Dan Brown. The novel Race the Pale Horse was written by the less-well-known Dan Brown.