linux
So I finally said goodbye to (k)ubuntu. It was a long ride, and lately I didn't like the direction it was heading: pushing unity and ads are just part of the symptoms of a bigger problem of politics. Anyway, I decided on Arch Linux - a distribution that is focused more on technical simplicity rather than wide-net usability.
It actually works incredibly good, it installs only the packages you need and not a single library more. I use KDE, and I was very surprised to see how well the build integrates with the rest of the system, even better than Kubuntu! I am a big fan of apt based packaging, and I must say that the pacman + aur system is at least on par.
Combined with the power of wiki pages they have, which are in abundance and probably contain solution for every common problem one may encounter, I would say this makes a sound alternative of Linux distribution for every advanced user.