"A Sound of Thunder", a short story by Ray Bradbury is basically the an archetypal what-if time travelling story. It's pretty short though, and doesn't bother to expand the story a whole lot.
Time Hollow, just as an opinion on the side, didn't really do well for its potential. :/
Everything just stopped just as it was getting exciting...
The Time Machine by H.G.Wells is also another example most would think about when talking about time travelling stories.