A Brief History of Time and The Theory of Everything by Stephen Hawking.Read about another entry on the list.
I'm interested in cosmology, technology, and science. These books, Hawking's explanation of the formation of the universe and a series of his lectures at the University of Cambridge, are difficult to get through but well worth it.
Alexander McCall Smith tried reading A Brief History of Time but couldn't do it. It is one of Iain Finlayson's top six books on time.