I love all three very much, but May is my favorite.
Unlike Misty, she spent more time battling, training, and competing than sitting in the crowd cheering her friends on. I loved Misty's fiery personality, but she never really got any closer to her goal until she left and took over her family's gym. May also seemed like she was more equal with Ash, as far as training and battling goes. She learned from him, but he also took some of the techniques he learned from her contest battles and applied them to his regular battles. She also found strong rivals who were just as fierce as his.
She has some of my favorite Pokemon too; eevee, glaceon, beautifly, skitty, wartortle, and blaziken and just love her character design.
But Misty and Dawn are great too.
Misty will always be one of my faves, she was the character I grew up with and she was definitely one of the funniest characters. Sometimes I miss the old, less mature personality she used to have.
I'm starting to really like Dawn too. She's a very relatable character. She reminds me of myself sometimes, she's always nervous and freaks out before her debuts and she doubts herself very often. But she always finds the courage to face her fears and keep fighting even though it might seem impossible.
