I'm itching to read a sci-fi novel for some reason. I haven't read much sci-fi in the past, in fact, the only one I can think of is Ender's Game. That being said, I do love sci-fi TV shows such as Firefly and Star Trek (DS9; it always felt more adventurous than the other Trek series for some reason).
I'm not looking for anything heavy, though if you have a really great recommendation, I wouldn't rule it out. I would love an adventure story, something like Avatar or Firefly. Dark sci-fi books are cool too.
Some books I like: Drizzt books (obviously), The Name of the Wind (Patrick Rothfuss), Song of Ice and Fire (GRRM), Pendergast novels (Preston Child), Michael Crichton books, Airborne (Kenneth Oppel), Hunger Games (Suzanne Collins).