>>28396257I think early Misty is the best, but May was the best in her overall season.
Dawn isn't terrible but she's retreads May a bit too much, and Iris is Misty without understanding why Misty worked. She's Misty's tsundere, with Max's obnoxious ego.
Cilan I might add is Brock without understanding why Brock worked. Tracey suffers from not really knowing what to do with him, but it balances out because his signature Pokemon got some good spotlight and was really memorable and had a clear story arc in mind.
Clemont, Bonnie, and Serena are all great this season because they feel generally unique to past companions.