inktea asked for my science fiction favorites, and yes, I have a few.
In no particular order except how they were on my (unalphabetized) bookshelf:
The Warrior's Apprentice - Louis McMaster Bujold
Foreigner (and the whole series) - C.J. Cherryh
Cyteen - C.J. Cherryh
World War Z: An Oral History of the Zombie War - Max Brooks (I would argue this is science fiction--disease hits modern world, society changes)
Islands in the Net - Bruce Sterling
Neuromancer, Mona Lisa Overdrive - William Gibson
The Reality Dysfunction, The Neutronium Alchemist, and The Naked God - Peter F. Hamilton
Starfish - Peter Watts
The Book of the Long Sun series - Gene Wolfe
The Madness Season - C.S. Friedman
Adulthood Rites - Octavia Butler
In Death series - J.D. Robb (guilty pleasure)
Liaden Universe series - Sharon Lee and Steve Miller (guilty pleasure)
Have Spacesuit--Will Travel, The Moon is a Harsh Mistress, Methuselah's Children - Robert A. Heinlein
Foundation and Empire, The Naked Sun - Isaac Asimov
Picnic on Paradise - Joanna Russ
Dancer of the Sixth - Michelle Shirey Crean
The Postman, Kiln People - David Brin
Tea from an Empty Cup - Pat Cadigan
Jumper (original) - Steven Gould
The Handmaid's Tale - Margaret Atwood
Ender's Game - Orson Scott Card
Skeen's Leap, Skeen's Return, Skeen's Search - Jo Clayton
Brain Plague - Joan Slonczewski
Vacuum Flowers - Michael Swanwick
Brasyl - Ian McDonald
everything by Jon Courtenay Grimwood
Snowcrash, Diamond Age - Neal Stephenson
Bellwether - Connie Willis (now part of Futures Imperfect)