"Many times I've heard 'This is fixed in the last Linux kernel, and in OpenBSD 3.2.'" – Michael Warren Lucas

You either want Qubes OS, OpenBSD, or TAILS. Qubes OS would better suit for a desktop use, especially with faster graphics and more packages.

You probably want OpenBSD for a secure-by-default server, that you would update every 6 months, provided that parallelism isn't what you need most.

TAILS is useful as a desktop OS again, if you're an activist. It's what I'm using right now.

Sure, Fedora or Ubuntu would be more secure than Windows. Keep in mind that Fedora is maintained by Red Hat (NSA) and Ubuntu is maintained by Canonical (Five Eyes, GCHQ).

I don't trust any other "security-focused" distro because I don't see why it would be more secure than Debian or RHEL, and I don't see how they are innovative, either.