I couldn't let Snoopy's mention of not liking Science Fiction pass without comment so here is:
Uncle Mort's top twenty* Science Fiction list (no particular order):
The Dispossessed - Ursula K. LeGuin
Up the Line - Robert Silverberg
The Moon is a Harsh Mistress - Robert A. Heinlein
Voyage - Stephen Baxter
Lord of Light - Roger Zelazny
The Man in the High Castle - Phillip K. Dick
Timescape - Gregory Benford
Pavanne - Keith Roberts
Stand on Zanizbar - John Brunner
A Canticle for Leibowitz - Walter M Miller
The Uplift War - David Brin
Dune - Frank Herbert
A Clockwork Orange - Anthony Burgess
The Anubis Gate - Tim Powers
1984 - George Orwell
Tiger, Tiger - Alfred Bester
To Say Nothing of the Dog - Connie Willis
Stranger in a Strange Land Robert A. Heinlein
Hello Summer, Goodbye - Michael Coney
Rite of Passage - Alexei Panshin
Give some a try Snoopy. You might enjoy them.
*I tried to keep it to 10 but failed