A Girl Like Sugar is amazing. I picked it up and read it in one sitting (coincidentally on a train, but that's another story). The guy next to me was surprised at how quickly i went through the book, but it's just that readable.
Chock-full of interesting, vibrant characters who are delicately drawn, A Girl Like Sugar, despite its almost over-the-top premise, is a book that any girl can relate to. Sugar's problems are our problems, expressed in a way we can never quite manage.
What stays with you is the vulnerability and power of self-expression, as demonstrated by Sugar. Light and amusing, the message you're left with isn't pure saccharine fluff.