I really don't hate any episodes. I think at worst, they're just "meh"
I have 3 tiers in order from best to worst
Goddess Tier
-Lesson Zero
-Sisterhooves Social
-A Canterlot Wedding (mostly for Part 2)
-Sweet and Elite
-Hurricane Fluttershy
-Luna Eclipsed
High Tier
-Hearts and Hooves Day
-Baby Cakes
-Super Cider Squeezy 6000
-It's About Time
-Cutie Pox
-Hearth's Warming Eve
-Return of Harmony
-A Friend in Deed
-Putting your Hoof Down
-Family Appreciation Day
-Last Roundup
-Mysterious Mare do Well
Meh Tier
-Secret of My Excess
-Dragon Quest
-MMMystery on the Friendship Express
-May the Best Pet Win
-Read it and Weep
-Ponyville Confidential
Of course, unlike Season 1, I haven't spent a lot of time rewatching episodes, at least not yet, so over the pony drought, my list could change.