I think Season One is the most holistic and purposefully-crafted season. I also think the show got better the more of the original rules it broke.
I was there during the initial explosion. Having gone back and revisited Season One, I’m confident that it was a really solid show. However, there was often a large disconnect between what the fandom was hyping up, and what actually made the show good. Season One was sort of doing its own thing, and I still think the show would have benefitted from either a time skip or a soft reboot immediately after Return of Harmony.
Another thing was that part of the magic was watching them spin gold out of corporate mandates. Hasbro wanted a fashion pony, so Faust created Rarity, who wasn’t in her original vision. It made it feel like the staff was getting away with something by making an awesome show, and that we were getting away with something by watching it.
What I’d really love to see is what the original team could have done with 26 episodes and a special if they didn’t have that ei restriction.