So I had to write a paper on a piece of popular culture and analyze it as a literary work for my literature class this semester and I did it on my favorite Book, Ender's Game by Orson Scott Card. This is one of potentially the best known Sci-Fi books.

I was wondering what others favorite Sci-Fi books are? I'm looking to read a few more good SciFi books as I'm in the mood. What should I read?