Next campaign, no over-arching mega-plot. Firefly style mission-based adventuring, old-school wander-into-trouble adventuring, whatever. But no "everything is connected, you must find the seven keys to activate the mystic dingus" adventuring.
I did it in the last campaign I ran. The campaign before that was heading towards it. I don't talk about the one before that, and the first campaign did also had that sort of ring to it, if memory serves.
It's worked out fairly well in all cases. But I lean on it; it's my comfort zone. So next time, the PCs are going to have a series of sometimes loosely connected adventures, and no one plot is going to take over the entire game.