Any episode with Moonhorse is a good episode in my book. the 19th episode of season 4 brought us some much needed Luna, with Sweetie Belle as the actual focus.
Following that, Flim and Flam made a return. I remember a lot of people liking this episode. It also introduced one of the Make a Wish foundation ponies with a stallion in a wheelchair.
Anyway, time for rewatch! Get your episodes on Dailymotion:
For Whom the Sweetie Belle Toils
Leap of Faith
And discuss below!