Well, Paul, Drew and... Zoey, I think I voted for.
Paul, is just, quite possibly, imo, the best thing that happened to the newest seasons. He's the only person (That I can recall) that has ever either made Ash doubt himself, or burn up in a fury unmatched by what anyone else could do. That, and he manages to beat Uberchu is epic.
Drew... well, he's the only rival for May that I remember. Haven't really watched much after Season 5.
Zoey... no real reason. Only saw her once, which is more then how much I saw Kenny, so... yeah.