If you're more into the space opera, the Deathstalker series is a great lengthy read, if poorly named.
"Stranger in a strange land" is an incredible read as well, but doesn't focus on the action side of sci-fi. Is considered a classic, as well.
If you're more into action-sci-fi, almost anything by Timothy Zahn is a good read (Allegiance, set in the star war's EU is one of my favorite EU novels)
Andre Norton was also a great writer, as well.
Just remember, don't judge a sci-fi novel by their shitty 70's style artwork. I'm looking at you, John Ringo >_<
"Stranger in a strange land" is an incredible read as well, but doesn't focus on the action side of sci-fi. Is considered a classic, as well.
If you're more into action-sci-fi, almost anything by Timothy Zahn is a good read (Allegiance, set in the star war's EU is one of my favorite EU novels)
Andre Norton was also a great writer, as well.
Just remember, don't judge a sci-fi novel by their shitty 70's style artwork. I'm looking at you, John Ringo >_<