Ranked in these QuestionsQuestion Ranking
Pro Supports custom hardened kernels
Your only real options for a widely supported hardened distro are the Red Had distros (Red Hat, CentOS, Fedora) of which Fedora is your best bet for a desktop , or Gentoo. You can make a hardened kernel in Gentoo while stripping unnecessary features, creating a much smaller attack surface, and using in-kernel mitigations others don’t.
Pro Comprehensive hardened guide in wiki
From SELinux to PaX to AppArmor to.... The wiki has got you covered.
Pro Fully customized kernel that prevents server-side malwares with SSO mechanisms
Out of CentOS /RedHat/Fedora a hardened kernel is very easy to make.
Pro Best defense against NOP-sled malwares, even with ROP/COP mechanisms
Out of CentOS/RedHat/Fedora/OpenSUSE/Slackware/FreeBSD/Mandriva and Arch, only Gentoo can best protect you against NOP-sled malwares, even with ROP/COP mechanisms.