http://www.sabayonlinux.org/
SabayonLinux is based on the source-based distro named Gentoo, so in order to understand the background of Sabayon, one must learn a bit about Gentoo.
On a pure Gentoo system, the kernel and every single application that is installed is compiled by that system, specifically for the system. By doing so, applications are leaner and tend to run a bit faster. This can be achieved through a Sabayon system by using Gentoo's package management, Portage.
However, compiling every application makes installations take much longer than binary installations. Many would argue that compiling does not offer enough of a speed boost to warrant the trouble. For those people, Sabayon also offers a binary package management known as Entropy. Entropy is still fairly young compared to other package management systems, but it has already proven quite capable (I personally use entropy as my package manager).
Well now, that's all fine and dandy, but what makes Sabayon so special? Good question. To be honest, besides the friendly and helpful community on the forums and on IRC, and the choice of package management, there's nothing that really stands out on Sabayon more than it's LiveDVD experience. Sabayon strives to provide the best out of the box experience that it can. It was the first distro to include Beryl (now replaced by Compiz-Fusion) on a LiveCD/DVD. If you pop in the LiveDVD and boot, you can run games, openoffice.org, firefox with flash, and so much more. You can get a feel for exactly how your system will behave after installing (except it will be faster post install). Most linux distro's have LiveCDs nowadays and some will claim that Sabayon puts too much onto their LiveDVDs. It's all about choice and Sabayon's goal is to show you as much as possible concerning what it can do before you even install it.
Even if you don't think Linux is for you, the cost of trying it out is one burnt DVD. Maybe Linux is quite as scary as you think.
Sabayon offers four different LiveDVDs two KDE versions (64bit/32bit) and two Gnome editions (64bit/32bit). I personally use KDE and would recommend giving that one a try if you just want to give linux a try in general.
