Blatantly copies GymLeaderLily's layout, but with slight changes. xD
Overall favourite: CLAIR! :D I like how she evolves as a character, and understands she won't only win. Plus she has a Dragonair and a Kingdra, though Juan has a Kingdra, h doesn't really appeal to me as much as Clair does. :\
Kanto Favourite:Toughie, because although they were the originals... none of them reall stood out to me. Probably Erika, because I like here personality, though Giovannie\Blue are up there too! :D
Johto Favourite: Clair (points to overall favourite)
Hoenn Favourite: Now, this is hard! Hoenn, in my opinion, was as stale as it gets. None of the ones were interesting, and when they tried to be interesting (e.g: Wattson), they just ended up being annoying (to me, anyway.) I'm going to have to say Flannery, because I think she looks pretty cool for a fire type gym leader, and I like the type she trains. I also dont mind Tate and Lisa, Norman (though I hate his Slaking with a passion, in both appearance and strength), Winona and Wallace\Juan.
Sinnoh favourites:Not that hard, really. The first Gym Leader that comes into my head is definitely Volkner. Not only was he pretty cool, I like how they gave him a bit of a backstory, too. Also, he has a Electivire <3 (in Platinum) and you get to battle him again with an elite four member outide the Battle Frontier (agan, only in Platinum). Byron was pretty cool to, and so was Gardenia and Candice.