"The Fortuneteller"
"The Headband"
"The Desert"
"Tales of Ba Sing Se"
"Nightmares and Daydreams"
"Ember Island Players" (though obviously I haven't seen all of it, that seven minutes had me laughing very hard. I've watched it at least ten times now)
"The Boiling Rock" part 2 (I haven't seen the first part yet. And I'll tell you why, even though it was supposed to be a somewhat srs business episode, it was so lulzy. The obvious Zukka hinting. Fishing? Can you make anymore Brokeback Mountains references, plz? And of course: Rocket!Azula pwns all when it comes to lulz.)