Yeah there's millions and we all have our favourites.
I particularly love Homer pretending to be Mister Burns:
Homer: "Hello, my name is Mister Burns. I believe you have a package for me."
Post Office worker: "Okay Mister Burns. What's your first name?"
Homer: "I don't know..."
Also Homer hitting the wall with a hammer, getting electrocuted.
"Man that hurt! Now to do exactly the same thing again!"
Burns (answering doorbell): "Come in! Welcome! (under his breath) Ah, excellent! Fresh victims for my ever-growing army of the undead!"
Smithers: "Sir, you have to take your finger off the button..."
Burns: "What? Son of a -"