BILL
Likely none of them, to be honest. I would quite honestly prefer to die than be involved in that sort of thing.
However, if I absolutely must, I suppose Team Aqua is benign enough. Or, at least, it’s as benign as one can be when summoning a legendary that can, in turn, summon relentless rain to drown the world. Their goals were noble, at the very least.
LH
Personally, I would side with Team Flare. While, yes, they nearly destroyed the world, on the other hand, it would be a prime opportunity to work with the Eliseo Lysandre, head of Lysandre Labs. Not only would it be enlightening to work alongside one of the most brilliant minds in pokémon technology (or … another one, for a change), but it would also be nice to see what our competition is doing for once.
{THE MUN
Probably Team Skull, just because unlike most teams, Skull is open about the fact that they are meme-filled trash.}