The best: powerful but unbloated

If you accustomed with nice, but unusable UI of other plugins (Wordfence comes to mind first), you will be surprised by UI simplicity and intuitiveness. But don’t bee fooled. This plugin is more powerful than it seems from the surface. Simple UI is a big plus for users, because it allows effective management (contrary to the WordFence).

Plugin is so effective, that I see a situation, where you can lock out even himself. It never happened to me, but be careful, whitelist your own IP. The Citadel mode is a really powerful feature.

Highly recommended, it works on the ClassicPress too (at least at this moment).