These movie accents are incredible! For this list, well be looking at the most challenging and out-of-this-world vocal changes that native English-speaking actors made for movie roles. Our countdown includes Margot Robbie, Robert Downey Jr., Lady Gaga, and more! Which of these actors pulled off their faux accents the best? Let us know in the comments.Watch more great acting videos here: Top 20 Greatest Acting Debuts in Movies: