A Wrinkle in Time is the only book I know of that actually starts with "It was a dark and stormy night" and is a fascinating read all the way through. Meg is the daughter of two scientists - her beautiful mother does experiments in her lab built off the kitchen, but her father has been missing for years and nobody will say why. Meg regularly has fist fights with anyone who disparages her father or her strange younger brother, Charles Wallace. It's through the introduction of new characters (especially an boy from school who becomes a close friend) that she begins to find her place in the world and that her unique blend of brilliance, stubbornness, and love for her family might be the only thing that can save them. 

This was hands down my favorite book through elementary and middle school. I have tried to read everything I can by Madeline L'Engle, and I love her books about the Austins too, but there's nobody like Meg. I love too how L'Engle allows her characters to not only grow up, but to meet each other too - they all live together in the same world. It's like meeting old friends. 

Illustration note: if you've read the book, you'll know why Meg is holding a folded piece of string with an ant in her hands. Her button shows a depiction of a tesseract, which in the book is the 5th dimension and the answer to rapid space travel.