Supreme Court Justice
Supreme Court Justices are paid just over $200k a year, and ethics laws related to "outside-earned income" for high-level government employees cap other earnings at 15% of annual salary. Bad news if you were planning to get on the Supreme Court just for the cold hard cash.
Still, there's a nice pension, plus the opportunity to rake in the dough after retirement. Books on legal issues or autobiographies by justices have sold well, and without that pesky conflict of interest, speaking fees can get quite hefty. It's certainly safe to say that the salary for a retired Supreme Court Justice vastly outpaces the salary for a current Supreme Court Justice. So hurry up and retire already.