Greg Keyes "Age of Unreason" series : "Newton's Cannon, A Calculus of Angels, Empires of Unreason, and The Shadows of God"
Don't judge Keyes by the Elder Scrolls novels, this series is intelligent, and sarcastically hilarious.

"The White Plague," and the "Dosadi Experiement" by Frank Herbert are also good sci-fi.

Hmm. Well, if your interested in a seriously long yet rewarding read, I'd recommend the Dark Tower series by Stephen King. It's his self-proclaimed magnus opus. While I couldn't classify it as "Science Fiction", it certainly has aspects of Sci-Fi in it, especially in the fifth book "Wolves of the Calla".

Here are two excellent lists of some of the greatest SF novels ever written:

(1) http://en.wikipedia.org/wiki/Hugo_Award_for_Best_Novel and

(2) http://en.wikipedia.org/wiki/Nebula_Award_for_Best_Novel

Some of my personal favs include:

A Canticle for Leibowitz
The Moon is a Harsh Mistress
City of Illusions
Planet of Exile
Left Hand of Darkness
The Dispossessed
Stranger in a Strange Land
The End of Eternity
Foundation's Edge
Dune
The Stand
Ender's Game
Speaker for the Dead
Hominids
Humans
Hybrids
Wastelands: Stories of the Apocalypse
Ringworld
The Ringworld Engineers
Slaughterhouse Five
His Majesty's Dragon
Yiddish Policeman's Union
The City and the City

Hi ya Fish




http://en.wikipedia.org/wiki/The_Difference_Engine -steampunk wise..


and Dr. Who is ALWAYS WORTH IT!! Now go, watch! :stare: