Term limits for every federal job.
I'd say term limits for Congress first. 12 years max. Two terms as Senator, six as Rep. Or three as a Rep, one as a Senator, don't care.
But that's never going to happen. You know why?
Because we're never going to get those jackwads in Congress to vote themselves out of a job. Such a thing would require a Constitutional Amendment and they'll never even let it out of "committee" much less for an up or down vote.
Even if it does pass, I'm not entirely positive you'll get the required number of States to pass it. I mean, those very same jackwads in Congress still have a lot of favors owed from their respective states.
Of course, the States could call for a Constitutional Convention and pass it that way, but that would turn into a straight potato free for all with every State trying to put in their own pet peeve or get rid of Amendments already there (the 2A comes immediately to mind). So, any Constitutional Convention will ultimately fail because...
You guessed right, contestant #1! The tribal ideologies!
It was like herding cats trying to set up a document acceptable to the 13 States and people think it's going to be easier when you toss in another 37 on top of that?