I guess i liked Misty the most, having endearing personality and many quirks which kept character fresh for me, and imo she brought great dynamics and humor to cast. She was feisty, spunky, caring, assertive and full of adventurous spirit often playing role of heroine by saving people lives, helping others about their problems and having great sense of humor.
I also enjoyed in growth through she went as character,starting as short tempered girl exploding over everything trying to cover up her insecurities with temper, with time gradually growing in more mature and confident character over time with various sides of her personality(beside only temper) being explored more still being quirky. Which led to some great character development with Misty gaining sisters respect getting over complex of feeling less worthy, getting over Gyarados fear, growing as water trainer coming in light of more confident and independent person(top 8 in Whirl Cup, winning Seaking championship, Alto mare race etc kinda confirming that she improved) while still having charm,etc.
I know its been long since she left cast, but part of me hopes we will see her again.
She has lot of untapped potential, leaving several things about her story unexplored and untied. Like goal of becoming water pokemon master which was unfinished existing several ways through which this dream could be advanced,potential to learn more about Misty seeing her grow as person,catch new pokemon and so on.
And i miss that unmistakable dynamic she brought to cast, being refreshing to see her interact with new characters and Ash after so long.
Now when i think about it becoming E4 or being taken as some powerful water trainer apprentice(like Lorelei)would be nice material to make story arc out of it and good way to wrap up character being as closest as shes possibly going to get in achievement of her dream. Since E4 are best trainers which use one type in world, and seems like logical step forward from gym position.