I've used Fabric, Chef, Puppet, and Ansible, and have settled on Ansible; it's a sort of middle ground between Fabric and Chef that does more than just run commands on servers but doesn't require me to buy into a whole elaborate universe of configuration management servers and whatnots. Ansible is great. The ZeroMQ stuff makes sense if you're pushing configurations inside a data center, but it's a dealbreaker for us…
reads article about A I've tried B, C, D, and E, and I like E.
And if you criticize me, I down-vote you. Classy.