Season 1, Episode 11 of Captain N has a lot of the questions about the mirror world, but this is probably one of the most amusing:
So in the mirror world has the chicken or the egg debate looped around forever too or has it been solved?
Season 3, Episode 7 of Captain N had the Prince pass out via magic potion, and had his face land right into his bowl of soup. The annotations noted that this was the only thing humorous in the third season. It got more hilarious after the annotators defended it when Lana said it wasn't funny.