I've read all these books except where indicated otherwise.

• The Hitchhikers Guide to the Galaxy
  (Hitchhiker's Trilogy 1)
• The Restaurant at the End of the Universe
  (Hitchhiker's Trilogy 2)
• Life, the Universe, and Everything
  (Hitchhiker's Trilogy 3)
• So Long and Thanks for All the Fish
  (Hitchhiker's Trilogy 4)
• Mostly Harmless
  (Hitchhiker's Trilogy 5)
• The Ultimage Hitchhiker's Guide
  (Hitchhiker's Trilogy 1-5+)

• The Foundation Trilogy (HB, PB)
  Er, haven't read yet.

• The Last Unicorn

• The Illustrated Man

Haven't read these yet.

• Darkover Landfall
• The Ages of Chaos

• Imperial Earth
  Haven't read yet.

• Lord Foul's Bane
• The Illearth War
• The Power that Preserves

• Stealing the Elf-King's Roses
  Haven't read yet.

• Pawn of Prophecy
  (The Belgariad 1)
• Queen of Sorcery
  (The Belgariad 2)
• Magician's Gambit
  (The Belgariad 3)
• Castle of Wizardry
  (The Belgariad 4)
• Enchanters' End Game
  (The Belgariad 5)
• Guardians of the West
  (The Malloreon 1)
• King of the Murgos
  (The Malloreon 2)
• Demon Lord of Karanda
  (The Malloreon 3)
• Sorceress of Darshiva
  (The Malloreon 4)
• The Seeress of Kell
  (The Malloreon 5)
• The Diamond Throne
  (The Elenium 1)
• The Ruby Knight
  (The Elenium 2)
• The Sapphire Rose
  (The Elenium 3)
• Domes of Fire
  (The Tamuli 1)
  The Shining Ones
  (The Tamuli 2)
• The Hidden City
  (The Tamuli 3)
   
• The Losers/High Hunt

• The Princess Bride

• Starship Troopers

Haven't read any of these yet.

• Dhampir
• Thief of Lives
• Sister of the Dead
• Traitor to the Blood
• Rebel Fay
• Child of a Dead God

• Douglas Adams' Starship Titanic

• The Eye of the World
  (Wheel of Time 1)
• The Great Hunt
  (Wheel of Time 2)
• The Dragon Reborn
  (Wheel of Time 3)
  The Shadow Rising
  (Wheel of Time 4)
• The Fires of Heaven
  (Wheel of time 5)
• Lord of Chaos
  (Wheel of time 6)
  
  Haven't read any of these yet:
  
• A Crown of Swords
  (Wheel of time 7)
•  The Path of Daggers
  (Wheel of time 8)
• Winter's Heart
  (Wheel of time 9)
• Crossroads of Twilight
  (Wheel of time 10)
• Knife of Dreams
  (Wheel of time 11)
• The Gathering Storm
  (Wheel of time 12)
• New Spring
  (Wheel of time 0)
• The Gathering Storm
  (Wheel of time 13)
• Towers of Midnight
  (Wheel of time 14)
• A Memory of Light
  (Wheel of time 15)

x3

• The Star Wars Trilogy

• A Game of Thrones
  (Song of Ice and Fire 1)
•  A Clash of Kings
  (Song of Ice and Fire 2)
• A Storm of Swords
  (Song of Ice and Fire 3)
• A Feast for Crows
  (Song of Ice and Fire 4)
• A Dance with Dragons
  (Song of Ice and Fire 5)

• Freedom's Landing (Freedom 1)
• Freedom's Choice (Freedom 2)
• Freedom's Challenge (Freedom 3)
• Freedom's Ransom (Freedom 4)
   
• Crystal Singer (Crystal Singer 1)
• Killashandra (Crystal Singer 2)
• Crystal Line (Crystal Singer 3)
   
• Dragonflight
• Dragonquest
• The White Dragon
   
• Dragonsong (Harper 1)
• Dragonsinger (Harper 2)
• Dragondrums (Harper 3)
   
• Moreta
• Nerilka's Story
   
• Dragonsdawn
• The Renegades of Pern
• All the Weyrs of Pern
   
• Chronicles of Pern: First Fall
• The Dolphins of Pern
• Dragonseye
• The Masterharper of Pern
• The Skies of Pern
• Dragon's Kin

Haven't read any of these yet:

• To Ride Pegasus (Pegasus 1)
• Pegasus in Flight (Pegasus 2)
• Pegasus in Space (Pegasus 3)
   
• Dinosaur Planet
  (Mystery of Ireta 1)
• Dinosaur Planet Survivors
  (Mystery of Ireta 2)
• Death of Sleep
• The Rowan (Tower and Hive 1)
• Damia (Tower and Hive 2)
• Acorna (Acorna 1)
• Decision at Doona (Doona 1)
• The Ship Who Sang

I have read some but not all of these books:

Witch World

• Witch World
• Web of the Witch World
• Three Against the Witch World
• Warlock of the Witch World
• Sorceress of the Witch World
• Trey of Swords
• 'Ware Hawk
• Horn Crown
• Year of the Unicorn
• Spell of the Witch World
• Jargoon Pard
• Zarsthor's Bane
• The Crystal Gryphon
• Gryphon in Glory
• The Turning I: Storms of Victory
• The Turning II: Flight of Vengeance
• The Turning III: On Wings of Magic
• The Key of the Keplian
• The Warding of the Witch World
• Lore of the Witch World
• Four From the Witch World
• Tales of the Witch World 1
• Tales of the Witch World 2
• Tales of the Witch World 3

Other Series

• The Shadow of Albion
  (Carolus Rex)
• Star Rangers (Central Control)
• The Last Planet (Central Control)
• Star Guard (Central Control)
• Night of Masks (Dipple)
• Forerunner Foray
  (Forerunner & Dipple)
• Forerunner (Forerunner)
• Forerunner: The Second Venture (Forerunner)
• Victory on Janus (Janus)
• Moon of Three Rings
  (Free Traders)
• Dare to Go A-Hunting
  (Free Traders)
• The Stars are Ours! (Pax/Astra)
• The Zero Stone (Jern Murdock)
• Uncharted Stars (Jern Murdock)
• The Time Traders
  (Ross Murdock/Time War)
• Mind for Trade (Solar Queen)

Other SFF/Fantasy Novels

• Brother to Shadows
• Dark Piper
• Garan the Eternal
• Here Abide Monsters
• Huon of the Horn
• Iron Cage
• Merlin's Mirror
• Mirror of Destiny
• Moon Called
• No Night Without Stars
• Quag Keep
• The Scent of Magic
• Secret of the Lost Race
• Star Gate
• Voorloper
• The X Factor
• Yurth Burden

More Andre Norton on my Sci-Fi/Fantasy for Kids page.

 

• Titan A.E.

• The Color of Magic
• Equal Rites
• Eric
• Feet of Clay
• The Fifth Elephant
• Guards! Guards!
• Interesting Times
• The Light Fantastic
• Lords and Ladies
• Men at Arms
• Mort
• Pyramids
• Small Gods
• Sourcery
• Witches Abroad
• Wyrd Sisters

More Terry Pratchett on my
Sci-Fi/Fantasy for Kids page.

• The Golden Compass
  (His Dark Materials 1)
• The Subtle Knife
  (His Dark Materials 2)
• The Amber Spyglass
  (His Dark Materials 3)
• Lyra's Oxford

• Haroun and the Sea of Stories

• The Unicorn Dancer
  Haven't read yet.

• The White Hart
• The Silver Sun
• The Sable Moon
• The Black Beast
• The Golden Swan

• The Hobbit
  (The Lord of the Rings Prequel)
• The Fellowship of the Ring
  (The Lord of the Rings 1)
• The Two Towers
  (The Lord of the Rings 2)
• The Return of the King
  (The Lord of the Rings 3)

• The Arabian Nights: Their Best-Known Tales

• The Harp of Imach Thyssel

• The First Chronicles of Amber:
  (Chronicles of Amber 1-5)
  Nine Princes in Amber
  The Guns of Avalon
  Sign of the Unicorn
  The Hand of Oberon
  The Courts of Chaos
• Trumps of Doom
  (Chronicles of Amber 6)
• Blood of Amber
  (Chronicles of Amber 7)
• Sign of Chaos
  (Chronicles of Amber 8)
• Knight of Shadows
  (Chronicles of Amber 9)
• Prince of Chaos
  (Chronicles of Amber 10)
   
• Wizard World

Er, same book.  The back of the one on the left looks like the front of the one on the right, and vice versa.  The art got flipped somehow!