Michael J. Fox fits the role of Marty McFly to a T. It is a story of time travel caused by the invention of scientist Doc Brown played by Christopher Lloyd. Although the movie is not a hard core sci-fi with the infused comedy in some situations, the logic is still there. The movie is a blockbuster hence it was followed by 2 sequels – II and III – which also earned in the box office.
It brought up an interesting idea: time travel could possibly alter future events, in fact, whether or not people even come into existence. But that leads to another question, "If people of the future will develop time travel, then have they already messed up stuff now?".