The episode where Mary Johnson gets on the ledge and plans on jumping. Or the episode where Arnold becomes a mean drunk.

I'd go with the Ledge episode.

NEITHER ONE!! Lord Jesus, if there's anything that I hate more in this world, it's when a comedy program decides to go all "dramatic"! If I want drama, I'll watch a drama, thank you very much! When I'm in a mood to laugh, I don't want to be blindsided by some lame-o attempt at melodrama....I WANNA LAUGH, DAMMIT!!!

Sorry about the rant, folks...I just needed to get that off my chest...

On another point, there was only ONE sitcom that was ever able to pull off the comedy-drama thing with any finesse at all..."All In The Family"! And "Welcome Back, Kotter", while it IS a good show, is no "All In The Family".

I'm done. Thank you.