ubuntu: http://www.ubuntu.com/download/help/install-desktop-latest

fedora: http://fedoraproject.org/en/get-fedora-options

linux-minthttp://www.linuxmint.com/download.php

mageiahttp://www.mageia.org/en/

debian (for advanced user):http://www.debian.org/distrib/

arch linux (for advanced user)https://www.archlinux.org/

PC-BSD unix (for extreme user)http://pcbsd.org/en/download.html

free-bsd unix (for extreme user)http://www.freebsd.org/