Blue Weirdo said:
As a Star Wars fanatic obviously that's on the top of my list.
Other great ones include Peter Sellers who just stole the show and the Berndete Peters epsidoe which features some of the best skits including one of the all time funniest muppet moments:
"And so it was... that the grasshopper drove his sports car to Flordia and the ant got stepped on."
I still crack up evertime I see that!
That was also the one where Piggy was up in the box telling Statler and Waldorf what to like(they could like Bernadette Peters but had to hate Miss Mousy, who did the duet with Kermit).
After the grasshopper & ant sketch, they were laughing at it, and Sam came up behind them and yelled "WILL YOU STOP THAT!!!". Waldorf replies sheepishly, "Why are they picking on us tonight?"
I don't know that I have a favorite. It's hard to narrow it down to just a few.