A Wrinkle in Time by Madeleine L’Engle is a 1960s book far ahead of its time. It captured some cool concepts about space, aliens, good vs. evil, and even spirituality. I read this book twice: once as an eleven-year-old, and once as a twenty-year-old. I loved it both times, but got more out of it the second time. A very neat YA fantasy read, which I recommend.