I'm an old man of 35, so I remember some specific skits that Sam was in:
I believe that Sam the Robot's first appearance was with Susan and the second Gordon (Hal Miller). Sam keeps insisting that Sesame Street is Mulberry Street where he is supposed to meet a cement mixer. He insists that he can't be wrong because machines never make mistakes.
David is aggravated because all of the appliances in Hooper's store are malfunctioning. In a fit of anger he says that he hates all things that are mechanical. This hurts Sam's feelings so he disguises as a tree so David will like him. David explains that he likes him just the way he is. (Who says Sam The Robot skits couldn't be heartwarming?)
Instead of a birthday, Sam celebrates his "wiring day" and everyone throws him a party.
David asks Sam to make him a Wet Paint sign for a newly painted chair. However, Sam cannot do it until David shows him by...well...making a wet paint sign.
What a shame that same was not around to greet C3PO and R2D2.