Sabayon GNU/Linux
Chances are you should be using Linux. If you don't already know/understand this, I'm not going to attempt to explain it here because the reasons for doing so are so numerous and critically important that a) it's too much for me to type out here, b) these reasons can be easily found elsewhere and c) it would distract from what I really want to tell you. That is:
You should run Sabayon Linux.
In case you are unaware, Linux is technically just a kernel. All a kernel really does is schedule and allocate resources. That's it. Here, let me say that again.
All the Linux kernel really does is schedule and allocate resources.
It knows how to talk to your CPU, RAM, video card, hard drive, etc, tells them when to do things and keeps track of whatever they're doing so it can tell them when to do things in a sensical manner.
When people say "Linux" colloquially, they're more often than not refering to a whole operating environment that consists of the Linux kernel and applications that run on top of it so that actual useful tasks can be accomplished. There are many different premade bundles of some version of Linux with applications. These are referred to as "distributions" or "distros".
The main factors that define and differentiate different distributions are target roles (desktop, server, embedded, general purpose), available support (commercial/enterprise, community, none), focus (conservative/stable vs bleeding edge/experimental), available software/package management and ease of use/defaults "out of the box". Most of these are inextricably linked to one another so try to follow along for the big picture.