M*A*S*H: The Series: 1x01 - The Pilot

No offense to George Morgan but I'm not sure I would have loved Mulcahy as much if the gaping mouth and bugged-out eyes had continued to be the bulk of his expressions. :P The fly swatting at the beginning was cute though. And let the name confusion begin: in this episode he is refered to as "Father John P. Mulcahy."