well, i would say team rocket, but they're kinda unorganized. they're just like, go out and take over that building. but team galactic has ranks, is organized, and has a set conquest.
battle wise, team galctic. picture if giovanni had mewtwo, the grunts had their annoying zubat, raticate, and ekans.
and if cyrus had palkia, dialga, and maybe giratina, saturn, jupiter, and mars, had toxicroak, purugly, skuntank, and all of those random golbat, and the grunts have their 1 or 2 pokemon. i definetly think team galactic.
TEAM GALACTIC!!!!!!