Giovani is the Mob Boss Team Rocket needs and the one you should expect. Ghetsis is absolutely insane and evil to the maximum, he almost seems out of place in the games compared to everyone else. Pretty sure the team flare boss is actually that fat guy who pushed the button not Lysandre... so I am not sure if i could say anything for flare... But assuming Lysandre actually was the leader of team flare ( because i pretty sure they were just working for a mutual goal ) then he would be an emotionally unstable Billionaire who is obsessed to the point of mass genocide about beauty. I prefer the previous 2.
Team Magma? Team Galactic? Team Aqua? I do not give a damn about them :O Although they probably had the best idea for how to accomplish their goals... had they not let you into the room with the lake legendaries they might have had a shot. Also technically original plasma could have won at any point they wanted to and it was mostly because of N that they did not.
" Don't curse the darkness--light a candle! When freaky aliens give you lemons, make freaky alien lemonade. "