Dear John by Nicholas Sparks
Published in 2006
This book is sufficiently challenging enough because it says that it has "temendous emotional depth". The story is deep and has extensive vocabulary that makes this book challenging.
I chose this book for 3 reasons. The first being that I have read Nicholas Spark's previous novels and have enjoyed them greatly. The second being that I really like love stories. The third being that it is a current novel relating to a significant situation that occured recently (9/11).