I've seen only a few but they were all pretty fun.
Johnny Gilbert's warm-up for the Jeopardy! College Tournament a few years back. I remember one line specifically that cracked me up: "Remember, we will be panning across your faces during the credits, so if you're here with some other guy's wife, then for your own safety, please get the hell out!" He told a story about screwing up a live commercial for psoriasis ointment on Bill Cullen's Price is Right ("...An exciting medical breakthrough for those of you with sorry asses!") And then he got to reading the slate. By this point excitement was fever pitch because, after all, it's the middle of Ohio and national TV shows don't tape here that often. He sensed the mood in the building, stopped in mid-slate, turned to us and said, "God, this is exciting!"
Rich Fields' warm-up for "The Price is Right" when I went to LA last April. I know the mixed feelings about Rich here, but I will admit being biased because he pulled me up onstage along with a woman in her 60s and declared us the Official Price is Right Dance Team. So I boogied in the Bob Barker Studio, and after the taping, three women my age who had come to the show in cheerleader outfits screamed "Nice moves, Adam! Wooo!" Damn, I miss Los Angeles.
And last year when "The All New High-Q" taped at Marshall University, some guy named Adam Nedeff did audience warm-up. Since the audience got to wait indoors and we fed them, they were already in a good mood, but Adam did a little spiel and then taught them a bunch of hand signals he'd be using to prompt different reactions, and then tested them by changing the hand signals at lightning speed until they gave up and began laughing. And there was a really funny blooper at one of the tapings where Adam stood up too quickly, oblivious to the fact that he tied himself up in a wire, and destroyed the microphone he was using while prompting the audience.