The fricking hamburger menu on desktop applications. I don't care if there's an option to use it or even if it's the default option as long as there's a way to get a traditional menu bar. But when it's the only option the designers can fuck right off. Monopoly and privacy aside, I'll never use Chrome just because I have to use a stupid hamburger menu.
I completely understand why it's used on mobile devices, and thus I get why it's used for non-mobile devices. People who are used to it from mobile want it on the desktop. Or maybe your vertical screen space is limited and it lets you get back a line of space for other stuff. But it's really just poorly re-creating the menu bar while requiring (at least) an additional click. When there's no good reason for it, it just sucks. Give me an option to use it or not!
I can't wait for my home state to have fair elections again.