Operation Luna
Poul Anderson
Operation Chaos (2)
Operation Earthworm
Joe Archibald
Open Sesame
Tom Holt
Only Forward
Michael Marshall Smith
One-Way Ticket to Nowhere
Leroy Yerxa
One-Eyed Jacks
George R. R. Martin
Wild Cards (8)
One Second After
William R. Forstchen
One Second After (1)
One Rainy Night
Richard Laymon
One Plus One Equals Eleven
G. C. Edmondson
One Jump Ahead
Mark L. Van Name
Jon & Lobo (1)
One Door Away from Heaven
Dean R. Koontz
One Degree of Separation
Karin Kallmaker
Once Around the Realms
Brian M. Thomsen
Forgotten Realms Universe (1)
On The Prowl
Patricia Briggs & Eileen Wilks & Karen Chance & Sunny
On the Loose
Christopher Fowler
Bryant and May (7)
On a Planet Alien
Barry N. Malzberg
Omega Squad: Targets
Karen Traviss
An Old-Fashioned Valentine
Kathryn Kramer & Shirl Henke & Cassie Edwards & Eugenia Riley
The Old Martians
Rog Phillips
Old Guard
Bill Fawcett
Bolos (5)