I used to like Windows a lot, but these days it only annoys me. Which is interesting, because every few years I'd try to work on a Linux desktop and give up in frustration. With Ubuntu 14.04 and Mint, I'm having a great experience with very little annoyances.
On Windows, I don't like:
* How the Windows key lost its ability for instantaneous search. I used to type Windows, a couple letters, and ENTER to launch a program. Now it takes many seconds for the first letter that I type to show up (on a 4th gen i7 with 8GB).
* Most file extensions got assigned to the obnoxious, brain-dead nee-Metro apps and, to add insult to injury, it's a pain to close them. Having to reassign those extensions to regular desktop (aka "Windows") apps is an example of the annoyances that Windows now imposes on users.
* In general it feels like 2 different OSs fighting each other. Despite what Julie Larson-Green promised, I didn't "get used" to it, I just put up with it when I have to, and mostly avoid it.
* How, despite being careful and having Windows Defender, it's almost inevitable to end up with some spyware/adware which is very hard to get rid of.
* That Windows pretends to boot up very quickly by showing the desktop, then starts to load a lot of services (the "real" bootstrap) and stays unusable for up to a minute. In contrast, Mint's GUI becomes fully responsive in less time than it takes Windows to show the login screen.
* The command-line app (I mean the GUI itself) is terrible and I don't think it has changed in 20 years. Yes, I know of the alternatives. None feels as good as what comes with Mint by default, and having to install them on each system I use is another nuisance.
* So many upgrades that require a system restart. No to mention the ones with serious bugs that enter an install-rollback loop that takes hours each time (like the awful KB 2919355).
In short, I've developed a negative Pavlovian conditioning to Windows.