Unexpected twists can work in plot driven novels where the readers are expecting to move quickly - but without a lot of mental effort or interest in the characters - through a story. Your example author Dan Brown writes pretty much the same characters in every novel. He also spins absolutely fascinating mysteries that people must know the end of.
Plot twists can also feel cheap to the reader. For example, O. Henry's short stories seem a little less than serious because as a reader you go along through the story until you get to a plot twist at the very end that you didn't see coming at all. Instead of being able to see yourself as clever for anticipating this twist you feel like the author held important pieces of information from you. If you do a plot twist, you have to give the readers clues along the way to the twist that it is coming, dropping hints of what it will be. This keeps your reader engaged. Edith Wharton does this in an absolutely stunning way in her short story "Roman Fever." There is a twist at the end, but if you are paying attention she hints at what it might be all throughout the story.
Most of my writing professors during college preferred that we turn in character-driven fiction. In character-driven fiction, the thing that draws the reader in is the protagonist's wants, needs, fears, dreams, hopes, and loves. What do your characters want? What keeps them from getting it? What do they fear? What is making their fears realized? Write a compelling character. Make your readers care about him or her. Take one of his or her deepest desires and thwart it. Bring it all to a conclusion where the character changes - his or her desires change, he or she breaks from the hope deferred, whatever you like. You'll have engaged readers.