This month, it is a really close call between two novels: Insurgent by Veronica Roth, and Dreamless by Josephine Angelini. But I think it has to go to Dreamless!
Why? Because it is so freaking-awesome! I loved Starcrossed, and I knew Dreamless was going to be awesome - but 'awesome' is a complete understatement. The book had everything a good novel needs: realistic characters, an epic plot, a page-turning mystery, and an author with a brilliant writing quality.
Although technically this novel is being published in the UK on 5th July, I read it this month, thanks to MKB, so that's why I'm putting it as this months BOTM rather than July's. As soon as it is released, I really recommend that you read it; you will be hooked right from the beginning. And if you're not? I will eat broccoli. (just a note: I strongly dislike broccoli.)