Of course, we enjoyed the take on French art house cinema in What a Way to Go, with a long explication of Shirley McLaine's charms in French rendered as "she is very beautiful" in the English below, but our favorite subtitle is from Jackie Chan's Police Story, Part II. Jackie Chan plays a Hong Kong police inspector assigned to work with a female, mainland counterpart. This means he has to speak Mandarin, signalled to us non-speakers by the appearance of Chinese subtitles along with those in English, for those speaking Cantonese and other dialects. After some banter and bonding, they can let their guards down, and Mr. Chan is advised, "You can speak Chinese now", leaving those of us English speakers either confused or amused. We thought they had been speaking Chinese, one dialect or another, all along.
For those unfamiliar, it might help to point out that there are several spoken Chinese languages, including Mandarin and Cantonese, but they are grammatically extremely similar and are written using the same symbol for the same word. While a speaker of one language might not be able to speak to another, but they can write messages to each other, assuming some level of literacy. Christopher Isherwood, in his account of his journey to China with Auden, Journey to a War, pointed out that if you did not understand what someone was saying, they would start writing character strokes on the palm of their hand. Of course, this would not work with English poets, but it sounds like a useful means of communication.