Now Wait for Last Year
Philip K. Dick
The Number of the Beast
Robert A. Heinlein
Lazarus Long (1)
Oath of Fealty
Larry Niven & Jerry Pournelle
The Oathbound Wizard
Christopher Stasheff
A Wizard in Rhyme (2)
Obsidian Butterfly
Laurell K. Hamilton
Anita Blake (9)
An Occurrence at Owl Creek Bridge
Ambrose Bierce
Ocean Under the Ice
Robert L. Forward & Martha Dodson Forward
Rocheworld (4)
October's Baby
Glen Cook
Dread Empire (4)
Odyssey
Homer
Ogre, Ogre
Piers Anthony
Xanth (5)
Old Tin Sorrows
Garrett, P. I. (4)
The Omicron Invasion
Edward E. Smith & Stephen Goldin
Family D'Alembert (9)
On a Pale Horse
Incarnations of Immortality (1)
On Basilisk Station
David Weber
Honor Harrington (1)
On the Beach
Nevil Shute
On the Oceans of Eternity
S. M. Stirling
Nantucket (3)
On the Surface
Robert J. Sawyer
H. G. Wells' Time Machine Universe (1)
On the Trail of the Space Pirates
Carey Rockwell
Tom Corbett Space Cadet (3)
Once a Wolf
Susan Krinard
Val Cache (4)
One Door Away from Heaven
Dean R. Koontz