"Ender's Game" and "Speaker for the Dead" by O.S.Card. (Do not touch Xenocide without a hazmat suit. And if you do, burn it before reading.)
"Snow Crash" by Neil Stephenson.
"Rendez-vouz with Rama" by Arthur C. Clarke.
If you're up for some thought-provoking stuff, "Stranger in a Strange Land" by Heinlein. Not the easiest read but your carve-out basically rules out "The Moon is a Harsh Mistress".
"Embassytown" by China Mieville.
EDIT: I forgot "Hyperion" by Dan Simmons.