Can't remember the name of the episode, but the one where Dee and Charlie steal Frank's meat from the fridge so he sets them up with something they can't figure out and go around trying all sorts of different type of meat to figure out what it was.
"Mac and Dennis: Manhunter", where they set up all kinds of traps for Cricket. And Frank tells Charlie and Dee that the meat they ate was human, so they've got the taste for human and they're always hungry, so they keep eating. In the end, it turned out to be wild raccoon and they got a tapeworm which was making them hungry!
My favorite is "Who Pooped the Bed?" because it makes zero sense and because it heavily features Artemis. "Nightman Cometh" is also a classic. I think what makes a good episode is one that is easily quotable.