I think there are two requirements that make a movie quote a famous movie quote:
1) The movie has to be a hit – A great line in a bad movie doesn’t make the cut. ‘I want the ball’ is a great line in ‘The Replacements’ but unfortunately not a lot of people saw that movie.
2) The line within the movie has to be a hit. The line has to stand out from all other lines in the movie to resonate with the majority of the audience so they all agree that it was a great line. – You’re going to face stiff opposition convincing others that ‘Is it a problem?’ is a great line within ‘The Dark Knight’
Thomas Duggan 