Andy Kaufman vs Jerry Lawler (July 29th, 1982)
Only somewhat settled into their late-night perch, Letterman & co. decided to book an old friend: meta-stand-up Andy Kaufman, then deep into his pro-wrestler phase. The host had also invited on Kaufman's nemesis, Jerry "The King" Lawler, who injured the comedian during a match the previous spring. After a lot of mutual trash-talking, Lawler stood up and slapped Kaufman right out of his chair. The feud between the two men was later revealed to be a hoax — but neither Dave nor anyone in the audience (or folks watching at home) knew it was all a put-on. The sense of danger and anything-goes chaos was palpable, and the incident made headlines. Letterman and Late Night had arrived.