Most students when told they would be watching a movie about economics, immediately think of Wall Street. I was not overly impressed with Wall Street as a teaching tool. It's mainly about greed, corruption, insider trading and the chase for money and power. Boiler Room is similar, in that the main character wants to make a lot of money as a broker, mainly so that he can impress his father, with whom he has a very troubled relationship. It's about floating of junk bonds and how people can be driven by the desire to make money, to the point of losing their life savings.
Of these four, I would recommend Other People's Money for its potential to lead to discuss the social responsibilities of corporations. I should warn you, however, there that there is some scenes/language in the film that I personally found a bit offensive, and that may be offensive to women students in particular (the relationship between Danny Devito and the female lawyer in the film is sexually charged in a rather inappropriate context).
Trading Places, in addition to a nice scene about the role of expectations in stock prices, can lead to discussions about marginal productivity and the role of the environment in shaping us. It's kind of a classic nature vs. nuture film, and highlights income and class differences as well. It's also a nicely done, enjoyable film.