Well, Chopper is naive, and his teddy-bear form is small, like a kid. Heck, even Usopp and Luffy's still kids. They're still boys, but boys who are fun to watch, not like the ones listed below.
Oh right, I forgot about the movies.
-Daddy the Father's Daughter (I feel silly typing that…)
-Apis
-Scorpion Man's kids
-Marine Chef-Trainee
-Fireworks girl
-Kid in Zoro's flashback
-Pumpkin Brats
-Kid-Who-Wants-to-Revenge-for-Mom from Adventure in Ocean's Navel.
-Kid from Movie 1, grandson of Oden Ossan
-Kid from Movie 2, the typical lost his parents and has to be returned home.
-Kid from Movie 3, who, again, lost his parents and wants to be a nakama of Chopper.
-Kid from Movie 4, who, AGAIN, lost her parents and lives with an old man (see connection with movie 1?)
Overall, I really hated:
-Pumpkin brats
-Movie 4's kid
-Scorpion Guy's brats
Anyone want to suggest a rating system for these abominations?