What is the best novel of Chetan Bhagat ?

I was quite moved by reading "My Half Girlfriend". Everyone is dreamy-eyed when it comes to "love". We want it to be perfect. The novel narrates a romantic story with a happy ending. Simple language but vivid expression made the novel memorable. It is a story of crossing every limit to achieve your true love. The setting of the novel shows a stark contrast from a village to the New York city. The story even highlights that love does not need a language but only empathy.