everyday stuff that is a pain on Windows:
- connecting to WiFi
- connecting to a network drive (why does it have to be so terrible on Windows?)
- ejecting a USB drive
- getting audio to stream wirelessly
- loading an email with outlook (how bad can an email client suck?)
- switching workspace, expose, and pretty much everything else that is accessed by a multitouch gesture
- setting up SSH
- connecting a projector / external display (the horror windows users go through when giving a presentation!!)
- changing your multiple display arrangement
- sharing an internet connection
- accessing a CD/DVD from another computer
- exporting stuff to PDF
- setting your default internet browser
- choosing default apps for file types
- getting a file from one computer to another over WiFi
- setting/calibrating the colors of your display
- quickly looking inside the contents of a file (quick look)
- getting POSIX-style shell access to your system (DOS-style is retarded)
- creating/mounting an image of a drive
- UI adapting to having one retina-resolution screen next to a standard-resolution screen
etc... etc...
Some of the most basic stuff is completely retarded on Windows, and just got 10x worse on Windows 8. Why in hell would you want to be forced to preview an image in full screen mode, then forcing you into tile mode, needing to push start and click desktop to get back to your shit.
And then the epitome of lousy UI design in Windows: WIZARDS. They are all over the place. Ugh.
Once you get accustomed to the likes of OSX or Ubuntu, it's rough to deal with Windows.