what's the best os for playing games like skyrim, fallout, and arma with mods

[jhud6403]

I'm building my first gaming pc to play games like skyrim with heavy mods
Want to know what will be the best os to achieve this.

This is my build. http://pcpartpicker.com/p/283CK8

 

[kimatahi]

I'm building my first gaming pc to play games like skyrim with heavy mods
Want to know what will be the best os to achieve this.

This is my build. http://pcpartpicker.com/p/283CK8

Win 8.1 64 bit