Wow, two very controversial (with latter being less so) episodes going against each other... I don't really like either of those with "Principal and the Pauper" being actually better in inner quality, but leaving a somewhat sour taste for me. "Mona Leaves-a" didn't really disgust me whole lot, but I didn't like the quality of the episode itself. I'll think about this for awhile
EDIT: Ignore the thread title error. This should be round 2A, not 1B.