If you're new to ansible, I just released a quite extensive set of roles (basic server setup, security hardening, firewall, mailserver, nginx from source, oracle jdk, scala, monit, ...) on github [shameless plug]. I was missing these when I started out, so I hope it will help others.
There's even a complete personal cloudbox setup (including an extensive idiot-proof tutorial) based on this included, as well as a vagrantbox to test the others.