The Wizard of Oz uses Phi Kappa Psi ritual throughout the movie, but you'll never figure out how or where!
Any documentary on JFK Jr. mentions the Phi Psis at Brown, where he was (re)colony president.
Breaking Away was written by a Phi Psi, and is based on a Phi Psi team that won the Little 500.
In the movie Animal House, the Omega house is the Phi Psi house at the University of Oregon.