Cynthia and Blue have really good teams compared to the rest (considering Blue's rematch team over his regular team, of course). Steven's is fairly well-put-together, though not quite as nicely. Alder's team is too wtf, and Lance and Juan's teams have really glaring weaknesses.
Between Cynthia, Blue, and Steven, I think Cynthia's team is the most balanced. Cynthia wins (though Steven's theme plays the whole time).
I claim to be the official Porygon2 of the Pokemon Black 2 board. Scientist MileRun: WaRy associate