For personal machines, I strongly prefer Windows. Windows has a UI that is reasonably fast(Though that's kind of dependent on hardware) and easy to navigate. It can run most games pretty well and has a pretty good kernel. However, I am biased towards windows because its what I grew up using and am most familiar with it. On the other hand, the later releases of Windows are notorious for being resource hogs. Many people are attracted to Linux because it is open source and anybody can tinker with it to make it better suit their needs. Some also argue that the resource management on the Linux kernel is far better. I'm not saying one is better than the other, but I prefer windows. It's just kind of a chocolate or vanilla type debate.
It all depends on what you want to do.
For a gaming station, Windows can be the solution.
Even if the distributions dedicated to the games under Linux begin to democratize.
For a Server, I will say Linux, then, according to his knowledge and skills, we must choose the Linux's "family" with which we have the most facilities.
For my part, I use GNU/Linux Debian and I'm doing pretty well for my use.