My Favorite...
Episode: The Key (the end when Humphrey is on the ledge)
Joke: "You tell the [French] President to leave that bitch at home." from A Diplomatic Incident.
Running joke: The idea of a "courageous" piece of legislation.
Runner-up: "I don't want a leak inquiry; I want to find out who did it!"
Minor character: Sir Desmond, because he looks like he should be wise but he's a total moron.
I didn't think television could get any better than Falty Towers or Blackadder until I discovered Yes, Minister. Greatest political satire ever!