Smoking

I don't like smoking. It is a disgusting habit and it kills people. In fact, probably the biggest reason the life expectancy of Americans is the highest it's ever been is due to the various anti-smoking campaigns and general understand of the long term negative effects to health. That said, smoking in movies is awesome. It breaks up dialog and gives a good reason to pause when words are supposed to be taken in. It is visual and contributes to atmosphere and tone - if that's what you're going for.