take the window min/max/close buttons on MacOSX and Ubuntu, which for some reason they decided to put on the left instead of the right which everyone has been made familiar with over the last couple decades.
That's pretty simple: the original Windows design is poor, because it's very easy to mis-click when trying to maximize and instead close your program, because some moron at MS though it'd be a great idea to stick the two tiny buttons right next to each other.
If you have a hard time figuring out how to use a window-close button on the left side, you're going to have a real problem when you're sat down at a Windows 8 or 10 computer with its "charms" and touchscreen-oriented UI.
Minor quibble, but I'm gonna bite:
The Ubuntu design is just as poor, because what the designers did was move all three buttons to the left. So you can still mis-click. Moving "minimize" and "maximize" to the left but leaving "close" on the right would have been much smarter.
BTW, you can edit the configuration in Ubuntu to change the button positions to the right. I don't think I've ever seen such an option in Windows.
One of MY pet peeves in Xubuntu are single-pixel window borders that make click-and-drag resizing very difficult. But those, too, can be edited.
There are even pre-designed console commands on the net: https://softsolder.com/2015/01/28/wider-borders-in-xfce-xubuntu/