I strongly suggest Kurt Vonnegut. Start with Slaughterhouse 5. All of his books are fantastic and not hard to read.
you might like Ray Bradbury - Something Wicked This Way Comes was apparently great, but I haven't read it. Farenheit 451 was also great.
For the 'sword and shield' stuff, I loved the Drangonlance series when I was a teenager - by Margaret Weis and Tracy Hickman. I also loved David Eddings' books - The Belgariad and the Mallorean.
Other great novels that aren't too taxing:
Aldous Huxley, A Brave New World
George Orwell, Animal Farm
CS Lewis's Narnia series
Gabriel Garcia Marquez, One Hundred Years of Solitude
Mary Shelley's Frankenstein
You also might want to try short stories - easily digestible and of good quality:
Anything by Edgar Allan Poe
Anything by Issac Asimov, especially I, Robot