I like the Warrior Cats series, they're in the young adult section.
Another great series in that same section is A series of unfortunate events. Hilarious. I read the whole series and still don't know what was in that darn sugar bowl.
The Dune Novels are nice too, very complex, I love that about them.
The Island of Dr. Moreau was quite interesting, well worth the read.
I also liked Asimov's robot series.