Soon after I looked for security solutions and found RSFirewall. I have since used it on every site I have build and I will continue to do so for as long as I build Joomla sites. The cost, while high compared to some extensions, is incredibly cheap when you factor in the hours it would take to restore the site in the event of it being hacked.
I am now far more diligent with my updates, however recently a third part extension was compromised across the web, ck forms, and many hundreds of sites were attached due to the sql injection attack used.
My sites were also targeted, before I learned of the exploit, but I was pleased to learn that RSFirewall had been protecting me the whole time.
If you only buy one extension for your Joomla site, make it this one. Take the advise of someone who has worked many free hours restoring websites due to hacks and don't make the same mistakes that I did.
Thanks for the great extension guys. I hope you continue to support it for many years to come.