The theme song itself was also pretty catchy. "Hey, it's Lamb Chops Play Along! So join the kids, and play along!"
"Funny Aneurysm" Moment: In one episode, Lamb Chop tries to convince Shari that she has pneumonia so that she'll stay home with her (Shari is unconvinced). Shari Lewis would die of pneumonia on August 2, 1998, while undergoing treatment for uterine cancer.
Crowning Moment of Heartwarming: From that same episode mentioned above, Shari and Lamb Chop spend the whole day together (since Lamb Chop didn't want to be away from Shari at all). Towards the end, Lamb Chop finally realizes that people need time to themselves but claims she can't think of anything that she likes to do on her own but with Shari's help, makes a paper chain of things she can do by herself. Using the paper chain as a metaphor, Shari tells Lamb Chop "No matter how far apart we are, we'll always be linked together." Watch the scene here (starts at about 5:42 in the video)
Fridge Horror: The idea that people would be stuck singing a song absolutely forever purely on accident.
Fridge Logic: The idea that people started singing "The Song That Never Ends" without knowing what it was when the song BEGINS "This is the song that never ends"...
Nightmare Fuel: To some people, the puppets look creepy enough to give you nightmares.
Tear Jerker: In one episode, Hush Puppy enters a sweepstakes to win a bike but winds up not winning in the end and learning that losing is a part of life. Maybe not that sad to an adult, but for any kids who had to learn that same thing, it may bring back painful memories of going through that experience.
Shari Lewis' death counts as a real life example.
Speaking of which, she recorded this song for the spinoff Charlie Horse Music Pizza after she was diagnosed with cancer. Have tissues beside you while listening to it.