Wow!!! 21 nominations!!! 
Er... because there are so many noms, I won't have the time to read and quote the "best" Amazon review of the book, so links will just have to suffice.
The Forever War by Joe Haldeman, nominated by Drake Tungsten
Lord of Light by Roger Zelazny, nominated by Starchild
The Left Hand of Darkness by Ursula K. Le Guin, nominated by Ramo
Tits-Out Teenager Terror Totty by Steven Wells, nominated by Lazarus and the Gimp - DUE TO NON-AVAILABILITY IN THE UNITED STATES, THIS BOOK IS NO LONGER ELIGIBLE. Sorry.
A Fire Upon the Deep by Vernor Vinge, nominated by Ajbera
Rendevous with Rama by Arthur C. Clarke, nominated by Imran Siddiqui
Glory Season by David Brin, nominated by GePap
Schilds Ladder by Greg Egan, nominated by St. Leo
In Conquest Born by C. S. Friedman, nominated by Boshko
Firestar by Michael Flynn, nominated by JohnT
The Hitchhikers Guide to the Galaxy by Douglas Adams, nominated by Harry Seldon
Voice of the Whirlwind by Walter Jon Williams, nominated by Wraith
The Mote in Gods Eye by Larry Niven and Jerry Pournelle, nominated by Mordoch
Starship Troopers by Robert Heinlein, nominated by Lonestar
Barefoot in the Head by Brian Aldiss, nominated by Immortal Wombat
Armor by John Steakley, nominated by Tuberski
Cyteen by C. J. Cherryh, nominated by jon miller
The Proteus Operation by James P. Hogan, nominated by dv8ed
The Stainless Steel Rat Wants You! by Harry Harrison, nominated by monolith94
The Diamond Age by Neal Stephenson, nominated by pchang
The Years of Rice and Salt by Kim Stanley Robinson, nominated by Stefu

Er... because there are so many noms, I won't have the time to read and quote the "best" Amazon review of the book, so links will just have to suffice.
The Forever War by Joe Haldeman, nominated by Drake Tungsten
Lord of Light by Roger Zelazny, nominated by Starchild
The Left Hand of Darkness by Ursula K. Le Guin, nominated by Ramo
Tits-Out Teenager Terror Totty by Steven Wells, nominated by Lazarus and the Gimp - DUE TO NON-AVAILABILITY IN THE UNITED STATES, THIS BOOK IS NO LONGER ELIGIBLE. Sorry.
A Fire Upon the Deep by Vernor Vinge, nominated by Ajbera
Rendevous with Rama by Arthur C. Clarke, nominated by Imran Siddiqui
Glory Season by David Brin, nominated by GePap
Schilds Ladder by Greg Egan, nominated by St. Leo
In Conquest Born by C. S. Friedman, nominated by Boshko
Firestar by Michael Flynn, nominated by JohnT
The Hitchhikers Guide to the Galaxy by Douglas Adams, nominated by Harry Seldon
Voice of the Whirlwind by Walter Jon Williams, nominated by Wraith
The Mote in Gods Eye by Larry Niven and Jerry Pournelle, nominated by Mordoch
Starship Troopers by Robert Heinlein, nominated by Lonestar
Barefoot in the Head by Brian Aldiss, nominated by Immortal Wombat
Armor by John Steakley, nominated by Tuberski
Cyteen by C. J. Cherryh, nominated by jon miller
The Proteus Operation by James P. Hogan, nominated by dv8ed
The Stainless Steel Rat Wants You! by Harry Harrison, nominated by monolith94
The Diamond Age by Neal Stephenson, nominated by pchang
The Years of Rice and Salt by Kim Stanley Robinson, nominated by Stefu
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