1984- George Orwell
Brave New World- Aldous Huxley
The Giver- Lois Lowry
The Ambassador's Mission-
The Rogue- 
The Traitor Queen- Trudi Canavan
The Tipping Point- Malcolm Gladwell
A Wrinkle in Time-
A Wind in the Doorway- Madeline L'Engle
Ender's Game- Orson Scott Card
Ishmael- Daniel Quinn
The Crystal Cave-
The Last Enchantment- 
The Hollow Hills- Mary Stewart
To Kill a Mockingbird- Harper Lee
Of Mice and Men- John Steinbeck
Prelude to Foundation-
Foundation-
Foundation and Empire-
Second Foundation-
The Gods Themselves- Isaac Asimov
Where the Red Fern Grows- Wilson Rawls
The Gammage Cup- Carol Kendall and Erik Blegvad
The Merchant of Death-
The Lost City of Fear- D.J. MacHale
Dream a Dream For Me Tonight- J.P. Maffei

Those are the ones I could think of for the moment in case you are looking for some good reads, oh and who can forget HP all seven.