While I still find him generally entertaining, I'm tired of every single Plankton episode following this format: Plankton is depressed that he can't steal the formula, comes up with a plan, comes very close to getting it but then is stopped. They're all the same, it's quite annoying.
So here's what I suggest: new types of Plankton episodes. Maybe they could involve him and Karen, which have happened a couple of times (KO, SSA, P'sR), but without attempted theft or even mention of the formula. Maybe they could start a story arc about him being successful for once. Maybe they could show him doing everyday things in his life, like how most characters plots are. He could still retain his evil personality and there could still be episodes about him stealing the formula, but there would be varity in his plots. Do you agree with me that they should at least occasionally make episodes about him doing other things besides stealing the formula?