Secure OS

Nowadays, probably the most secure OS are hardened Linux systems (like hardened gentoo and RHEL), Trustes Solaris 11, OpenBSD, QubesOS, Novell NetWare and OpenVMS.
What do you thing is doing the best security approach of this OS.
And what do you thing is better in practise?
(You can also include other OS you consider secure)
And what do you think os security on microkernel systems?

If iOS was truly secure, there'd be no jailbreaking and Apple would control you.
If Windows was truly secure, you wouldn't be able to do what you wanted with your machine.
If the TCPA had its way and developed something truly secure, "your" computer is no longer yours.

Those who give up freedom for security deserve neither.

Fuck "security".