The Original Marty McFly.
It's arguably the best-known part of the Back to the Future lore. Director Robert Zemeckis wanted Michael J. Fox to play the lead, but the young actor was simply too tied up with the hit sitcom Family Ties. So the acclaimed star of the movie Mask, Eric Stoltz, was cast as Marty McFly instead. What's lesser known is exactly how much of the movie was shot with Stoltz, who learned to skateboard and play guitar for the part.