Gillespie informing Sam that he's arrested a cop. "OH, YEAAAAAAH!" What's funnier is, Sam doesn't seem to realize he's being dressed down.
There's one shot in particular that sums up Gillespie's day-to-day job, during the mid-bridge intercept of Oberst: Harvey running for his life, then turning to see that Gillespie is right behind him in his patrol car, the bumper about a foot from his own legs.
When Tibbs asks Harvey where in town one might go if they got a girl pregnant, Harvey suggests the town barber, so he can "help slit your throat."
An episode in which they arrest a serial polygamist, who used his charm and career as a travelling Bible salesman to maintain what turns out to be at least seven or eight households... all of whom descend upon the Sparta jail en masse bearing goodies... then he gets poisoned.