The fight scene near the end of "Undercover Brother" when Eddie Griffith and Chris Katan are taunting each other and "Beat It" is playing in the background. Then Eddie Griffith loses a hunk of his afro and says "You touch the fro, you got to go!" Classic.
Another favorite is the "day after" telephone call scene in "When Harry Met Sally."
Haven't seen Undercover Brother.
When Harry Met Sally was great.