"Back to the Future" 25th Anniversary: Challenges and Favorite Quotes

NEW YORK (CBS) The cast and filmmakers of "Back to the Future" reunited on Monday to mark the 25th anniversary of the first film, and they had a lot to say about the movies - including their favorite quotes.

Christopher Lloyd revealed his was "Roads? Where we're going, we don't need roads."

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[Watch a video of the cast saying their favorite lines below]

Lea Thompson chimed in next, saying, "Oh my God, it's Calvin Klein - what a dream!"

Finally, Michael J. Fox shared his favorite quip from Marty McFly: "You made a time machine out of a DeLorean?"

Director and co-writer Robert Zemeckis also talked about the biggest challenge he faced while making the film.

"Michael was working on a TV show all day, and then he would be picked up by a car and brought into the studio to shoot 'Back to the Future' all night," Zemeckis explained. "And I think the most difficult thing for all of us was that we had to make the whole movie at night."

He continued, "Even when we were shooting on the stage, we were shooting in the middle of the night. And all the scenes we did that were in the daylight were done on Saturdays and Sundays. So the schedule was the hardest thing - I think it was the hardest movie I've ever made, because of that."

The cast also discussed props they kept (or wish they'd kept) from the films, the trilogy's impact and what their characters would be doing now, a quarter century later.