Selling life-saving drugs at large multiples of the cost to manufacture + distribute. The most obvious example being insulin.
Switching political party in the same term that you were elected to office.
CEOs making 100x the median worker at the same company.
Assault rifles and other automatic or military-grade weapons. They have no practical purpose in the hands of a citizen. Pistols, shotguns, and hunting rifles should be sufficient for hunting and self defense.
Generic finance bro bullshit. Frivolous use of bank credit for speculative investment. Predatory lending. Credit default swaps. It's just a spectrum of Ponzi Schemes. Let's reinstate the Glass-Steagall Act.
Non-disclosure of expensive gifts to Supreme Court judges. Looking at you, Clarence.
Military recruiting at high schools.
Junk mail. You literally have to pay a company to stop sending it.