Could you please recommend me a science/fantasy novel?

It seems you're a pretty advanced reader. Anything by H.G. Wells is pretty good science fiction. The best ones are The Time Machine, The Island of Dr. Moreau, and When the Sleeper Wakes (I didn't really like War of the Worlds that much though, but that doesn't mean you can't like it.) Metropolis by Thea von Harbou is also awesome. It is the source for Fritz Lang's 1927 silent film.