This article is from the The Terminator FAQ, by Karsten A. Loepelmann firstname.lastname@example.org with numerous contributions by others.
Larry Niven's short story entitled "All the myriad ways" (in a collection by
the same name) explores the every-change-in-history-creates-an-alternate-
universe idea. The story is based on the idea that there are an infinite
number of these universes, branching off at every decision anyone ever makes.
It's an interesting extension of just how irrelavant everything become in one
of these alternate-universe-based view of things.
In that same collection is another story, "On the theory and practice of time
travel" which is a very entertaining look at the whole subject. The book is
highly recommended based not only on its high entertainment value but on its
thought-provoking look at time travel.
Robert A. Heinlein's short story "All you zombies" (in "The Unpleasant
Profession of Jonathon Hoag") is widely considered to be *the* definitive
time-travel story. Also, see "By His Bootstraps," (in "Adventures in Time and
Space") written under the pen name of Anson MacDonald.
"The Man Who Folded Himself" by David Gerrold was mentioned by quite a few
people; Phineas <email@example.com> describes it as, "quite a trip."
"The Time Ships" by Stephen Baxter (1995) is notable because it is a sequel
the seminal time-travel story, H.G. Wells's "The Time Machine".
The inspiration for the Terminator films can be found in some of the early
"Outer Limits" episodes. These shows are available on VHS video.
"Demon With a Glass Hand" [Writer: Harlan Ellison] [Director: Byron Haskin]
When the future Earth is conquered by an alien race, a lone survivor--an
intent, enigmatic man named Trent--finds himself thrown back a thousand
years into our present. Trapped in a delapidated office building, he
holds the fate of mankind in his hand--a mysterious, incomplete glass
hand that is both computer and oracle.
"Soldier" [Writer: Harlan Ellison] [Director: Gred Oswald]
Somewhere is Earth's distant future: on a blasted, radioactive
no-man's-land, two soldiers battle in a crossfire of death beams, and a
bizarre time-warp is created. Wrenched out of the future, flung back in
time to today, Qarlo is a killing machine without a war.
"The Man Who was Never Born" [Writer: Anthony Lawrence]
[Director: Leonard Horn]
A horribly mutated man from the future returns to the "present" to try
kill the man who created the biological disaster that led to the desolate