In a movie theater, how much talking would you tolerate from others before you ask them to "please hush."?

This is a general question, not specific to any situation. When you are in a movie theater, how much talking will you tolerate from others before asking them to hush?

(I ask because today I saw “The Help” and there was an older couple sitting behind me, and they didn’t talk constantly, but they commented on the various actors and scenery (“that’s so and so” and “isn’t that beautiful”), and they gasped a lot, which was annoying but I didn’t think it was anything to comment on – but it made me think about moving)