Business Pundit has put together a great list of business-related movies. He lists a number of good finance-related ones that I bring up (and sometimes show clips from) in class. They include:
Other People's Money, with one of my favorite finance film characters (Larry the Liquidator) giving one of my favorite speeches.
Wall Street, with the immortal Gordon Gekko's "Greed is Good" speech.
Stand and Deliver (not really a business movie, but still one of my favorites).
Trading Places (with my favorite trading floor scenes ever).
Glengarry Glen Ross, with another great speech (Caution - not safe for work)
It's a Wonderful Life (a great illustration of an old fashioned bank run)
For another list, go to Larry Ribstein's BusFilm site.
HT: Newmark's Door