None. Team Rocket should have left after the Johto arc was over with IMO. Team Rocket is not relevant in any other generation, so it's pointless to me for them to keep returning to each region, and every episode. Team Magma and Team Aqua could have been better during the Hoenn Arc, Team Galactic during the D/P arc, Team Plasma during the B/W arc, etc. Maybe have a 'new' Jessie and James for each generation or something.