I wouldn’t say entire series for FiM
I think that still belongs to Mr. M.A. Larson (Even if not all his episodes are all that great. Ex: Super Speedy Cider Squeezy 6000 (Granted I don’t hate that episode, all of M.A. Larson’s episodes even the ones that are definitely weaker compared to his big ones though have some degree of enjoyability. While I don’t like Swarm of the Century that much, I admit it’s probably one of the funnier episodes of the first season.)
It’s just his episodes prior to Season 4 for maybe the exception of Too Many Pinkie Pies aren’t considered favorably by fans of the show. Feeling Pinkie Keen and Over a Barrel both were funny episodes. But while Feeling Pinkie Keen got way more flack then Over a Barrel did, they both were overshadowed by the fact some people misinterpreted the episode as dumbing down of controversial political views. Like Feeling Pinkie Keen with religion, and Over a Barrel with the Native Americans Vs. The Settlers issue. (This was one reason why I was a bit worried about Bats! before it aired because it both had a writer that’s not that well-liked (Merriwether Williams) and it covered the issue of Pest Control Vs. Animal Rights)
We didn’t see Dave Polsky again until Season 3 with Too Many Pinkie Pies which other then maybe the part where Twilight blasts the clones in the Watching Paint Dry thing. Is relatively safe from the usual Dave Polsky controversy.
But then you get into Keep Calm and Flutter On where if there’s one thing other then Alicorn Twilight that the fanbase is split over, it’s if Discord should of been “reformed”. Especially in the way how quickly it seems to happen in Keep Calm and Flutter On. To this day, Keep Calm and Flutter On seems to be one of those episodes that’s good or bad depending on your mood. Like I feel Keep Calm and Flutter On was a very funny episode, it just gives this vibe of conflicting feelings until we see everything that’s in store for Discord in the future. Don’t get me wrong, I’m actually kinda happy we got to have more Discord. I thought he was great in the opener and even in Three’s a Crowd. It just feels like we’re still waiting just exactly what Discord’s purpose in being brought back is. Some are saying he’s there to be the ultimate challenge in Twilight’s friendship studies (Having to live with a being that seems to not be all too interesting in friendship in the first place) but until that’s made clear. We can’t confirm that.
Anyway, lastly there was Games Ponies Play (I’m skipping Spike at your Service, because as it turns out. Dave Polsky wrote the original version when Spike was going to serve Rarity, not Applejack. The script that was denied because Rarity was too mean to Spike. Though considering Putting Your Hoof Down was approved, I’m actually a little curious on just how mean it was. So Merriwether Williams, not that she needed a lower reputation, probably gets more credit for the final product we got) which while probably didn’t have any controversy. It was a really, really, average episode. As nothing really stood out too much, we even found out later the episode was rushed. Which is why we got the fast ending it had.
However in Season 4. For the exception of Daring Don’t which while I think it’s still a good episode it does have the mixed reactions toward Daring Do actually being a real pony instead of fictional in an already fictional universe. Rarity Takes Manehatten, Twilight Time, and now For Whom the Sweetie Belle Toils have all been at least pretty good episodes. I don’t know what Dave Polsky did between Seasons 3 and 4 that’s made him improve so much at writing FiM, but I hope it certainly continues. ^^