For today's choice, I was very tempted to go with Amazon's fabulously passive-aggressive email telling us to email Hachette's CEO. It's the best work of fiction I've read all day. Unfortunately, it's not a book, so I'll have to go with something else, which means I've got to work out what "powerful" is.
To me, a powerful story is one which immerses me in the world of the protagonist, which engages me whatever they're going through and which leaves me feeling differently about things. I have two books in mind. The first is Rachel Joyce's The Unlikely Pilgrimage of Harold Fry because it's done so perfectly.
But my pick - despite my wanting to try and steer away from books which are already popular - is Caitlin Moran's How To Build A Girl.
There is a section near the end of the book in which she talks about cynicism and what it does to you, and it not only made me weep hot buckets of salty tears all over my keyboard - and is making me well-up now, dammit - but which made me consciously go out and change something. Off the back of those pages I realised some things about myself and I made the active decision to be different.
And now I feel powerful. And I have a dress covered in Unicorns.