I just released a whole bunch of roles (basic server setup, security hardening, firewall, nginx (from package or even from source - fully customizable with modules), mysql, python, postfix, dovecot, oracle JDK, scala, vpn,…) I have been writing them and used/tested them extensively over the past couple of months. You can find the here, and they should benefit anyone looking to learn from example or cut time in writing scripts themselves.
Addendum: based on the above, I wrote an idiot-proof tutorial and script to set up your own personal server (secured mail, webserver, vpn, …).
Off course: open to comments and (pull)requests!