Network
Network is a satire about the television industry's prioritization of ratings over ethics, but the main take isn't about TV, it's about greed. The whole film follows a mad prophet, rather than getting the man help, they learn to monetize him.
"You have meddled with the primal forces of nature, Mr. Beale, and I won't have it!"
Some of the best dialogue I have ever heard in a movie. Everything said could be put into a quote book.