I run ClearOS on all of my ESXi hosts, I love it. I wish it had IPv6 support since I've been moving everything over to IPv6 since Comcast dumps all IPv6 traffic over to Level3 so I get half the hops that I do over IPv4 at home.
I don't think anyone in this thread has mentioned Elementary OS, a Linux distro with possibly the best desktop environment I've ever seen. Imagine OSX, but without the decade old quirky bullshit that is vaguely associated with Steve Jobs.