4. M*A*S*H - O.R.
The Early seasons of M*A*S*H are arguably the most simple the show had to offer. Still very much imprisoned in the formula cliches of a sitcom, the drama and cynicism of the movie it was based on had yet to be introduced. O.R. is the first episode to really breach the gap between escapism and reality that M*A*S*H struggled with in its early seasons. Set entirely in the Operating Room during a massive deluge of casualties, O.R. is the episode that proved M*A*S*H had more on its mind than simple comedy. Set in a war-torn South Korea, the humor of M*A*S*H has always had a very clear function - to distract the main characters from the horror and death going on around them. In order to sell the comedy, the network decided to put in a laugh-track, so that audiences would not be thrown by the bleak setting. O.R., however, removed this Laugh track completely - the first episode of the series to do so. Without the audible cue for humor, the joking around by the characters seems that much more futile and hollow, a desperate attempt to remain sane in an insane situation. What makes O.R. a great episode can be best summed up in this line, which Psychiatrist Sidney Freedman says to Hawkeye after the latter has lost a patient: "Some patients insist on dying, Hawk. You knew that going in. But you had to be a doctor."