Back to the Future: This Guitar Didn’t Exist Yet
This film is universally-acclaimed. Who didn’t have fun watching Marty McFly travel in time, meet his mother, and fall in love with her? In spite of the CGI being poorly-done, it has achieved the modern classic status. However, it seems the time travelling confused the crew as well. There was a scene set in 1955 where Marty plays a Gibson, but the model he used didn’t come out until 1958.

Back To The Future
Schindler’s List: Women Didn’t Shave Then
This movie would top all the best movies that have ever been made. The film won a lot of awards at the Oscars, but it didn’t get any for costume design. This might be due to a specific wardrobe error. There were questions on how female characters shaved their legs and armpits. Although this practice has become common in modern times, women in the concentration camps most likely didn’t have the luxury.

Schindlers List