Oh, wow, "Goodbye, Farewell and Amen", that was HUGE. For one thing, MASH in syndication played in New York every weeknight at 11:30 pm, so I saw that every single night from high school on, I can recite whole speeches verbatim (I'm thinking specifically of Hawkeye's "I will not carry a weapon" rant). Now that I think about it, there are still lines that my family and friends use that are just shorthand references to scenes from MASH (I can go out, and I can come in, out, in, out, in...). So when this episode aired--well, I was in college and had a class the evening the episode was going to air, and I remember the prof asking if there was any point in his coming in that night. (There was not. He canceled the class.)
I think I need to rewatch that finale sometime soon...