Many outstanding books have been mentioned on this thread. Since UtahDogJogger asked for our favorite books, I will take a different approach and list five favorites from my collection based on their value and historical significance.
Snell, Peter, and Garth Gilmour. No Bugles No Drums. Minerva Limited, 1965.
Autographed by Snell, Gilmour, and Arthur Lydiard. Very Good. The centerpiece of my collection.
Moore, Kenny. Best Efforts: World Class Runners and Races. Doubleday, 1982.
I own both a Good+ copy of the first edition and inscribed to me from Kenny Like New paperback 2nd edition.
Goldman, William. Marathon Man. Delacorte Press, 1974.
The novel which inspired the film starring Dustin Hoffman. A pre-press release copy in red card stock binding. Good+ as the spine has some fading.
Martin, David E., and Peter Coe. Training Distance Runners. Leisure Press, 1991.
Very Good hardcover, and a paperback reading copy with my notes and scribbles.
Bresnahan, George Thomas, and Waid Wright Tuttle. Track and Field Athletics. C. V. Mosby Co., 1937.
First edition of a classic that has eight editions. Good.