When I was about 9 or so, my grandmother gave me an old hardback edition of Carl Sagan's Cosmos. That was really the start of my interest in space in general and my love of theoretical literature from the likes of Graham Greene and Stephen Hawkins. Its pretty woefully out of date at this point, but there is an imagination that plays out that you don't find too often in recent publications. PBS released a documentary based on the book, hosted and narrated by Sagan.
Below is a great video tribute to Carl Sagan based on his "Pale Blue Dot" narration. There really is something touching there that speaks to the higher levels of humanity and altruism.