My vote's with CSF. Its integration with WHM/cPanel, not to mention there's a WHMCS module for customers to unblock themselves. It's been rolled into a complete solution.
I also like to install Fail2Ban and employ bitninja wherever possible. Oh, and don't forget to change your default SSH port, unless you like logging into your boxes and it shows thousands of failed login attempts since you logged in yesterday lol.
CSF is by far the better solution, and the developers are all over new threats and stuff with their other solutions, so it's always nearer the cutting edge features whilst offering rock solid reliability.
They natively support cPanel and DirectAdmin, so it's a nobrainer.