One that sticks with me is the Be More Chill performance on GMA. They changed "How was class? / You look like ass / What's wrong?" to "How was gym? / Girl, you look grim / What's wrong?"
The show that handled it best was Beetlejuice. They had a new lyric for basically every tv performance they did, from the Today Show to the Tony Awards, and I honestly like some of those lyrics over the ones in the real show, like the one at the Macy's Thanksgiving Parade:
"You're doomed, and so's your turkey
One day breathing, next, you're jerky
The Netherworld's like Albuquerque,
The queso's amazing,
The whole giving thanks thing!"