Personally I really liked the episode titled "Three Wishes for Opie." It had several twists and turns, some hilarious scenes, and a great surprise ending, which I won't spoil. I hadn't seen this for so long that I had nearly forgotten about it, and I had forgotten most of the details until I watched it again recently.

One subtle goof, though: in the scene where Goober, Barney and Floyd are sitting at the table and Barney lights the "magic" lamp, their shadows on the rear wall are incorrect, indicating that they were made by set lighting rather than the lighting of the lamp. Goober is sitting to the left of the lamp, so his shadow should be over his right shoulder. Barney is sitting behind the lamp, so his shadow should be behind him. And Floyd is sitting to the right of the candle, so his shadow should be over his left shoulder. But all their shadows are slanted toward the right, indicating that there is a set light off camera to the left of the three actors.