The end of the episode with Sammy Davis Jr: He kisses Archie on the cheek, cueing a Heroic BSOD. The studio audience laughed for so long, actually setting a record, that the laughing had to be shortened for the broadcast version.
In one episode, Archie finds himself locked in the basement. With nothing else to do, he drinks himself stupid and when a fireman comes to bust him out, he's so wasted, he thinks it's God coming to take him to Heaven. Then the fireman in question turns out to be...black. When Archie lays eyes on him, he immediately drops to his knees and cries, "Forgive me, Lord!" In an odd way, this also doubles as a Crowning Moment of Heartwarming, and possibly a Tear Jerker.
Even funnier is his followup comment, which closes the episode: "The Jeffersons was right!"