You might also consider 'The Identity Man'. It showcases Klavan's ability to create a unique and engaging story. It has elements of mystery and action that are sure to draw you in and give you a taste of what his other novels are like.
If you like crime - based stories, you could start with 'True Crime'. It's a good introduction to Klavan's style of writing, with a strong plot and interesting characters.
I would recommend 'Don't Say a Word'. It has a relatively straightforward premise that quickly builds into a complex and suspenseful story. It's not overly long, so it's a great way to get a feel for Klavan's work without a huge time commitment.