Well, imo overall the series declined in later seasons and wasn't that enjoyable for me, I especially don't like when the character goes through development and then suddenly reverts to their 1-season self, lol.
But I liked Discord as a villain in the beginning, and his friendship with Fluttershy was interesting, plus him playing D&D-like game in the show was great imo! What I liked was that despite Discord seemingly got a heel-face turn, he was still an agent of chaos, and to me he's forever chaotic neutral.