Which episode of LnC do you think showcases Clark's character the best? Which gives us the best demonstration of his personality, his emotional strengths and weaknesses, his quirks, etc.? One you could point at to show someone "That's Clark"?

Green, Green Glow of Home. It shows him as his most human. In this way, Ultra Woman would also be a good companion episode. Both show how he'd still want to help out even without powers.

In terms of strengths and weaknesses, Fly Hard would be a good example. He still has his powers but he cannot use them.

The pilot episode. It shows Clark pre-Superman, shows him as himself (in Smallville, he didn't even need to wear his "I'm only human" disguise), shows his hopes and dreams for himself, and shows his motivation for becoming Superman. It also establishes his relationship with all of the folks at The Planet.

Joy,
Lynn

I've always liked "The Eyes Have It", where Clark is blinded. Faced with this stunning blow, he nevertheless says to Lois that he's going to be the best person he can be (or similar words.)